I often work together with large enterprises helping them train their IT staff in wireless technologies. And the message I send regularly is that there is absolutely no value in upgrading their wiress for new standards rather than growing their existing infrastructure to support better service.
I have recently begun training telecoms on planning for 5G installation. And the message I generally send is "people won't really care about 5G" and I have many reasons to back this up.
Understand that so long as pico/nano/femto/microcells are difficult to get through regulation in many countries, Wifi will continue to be a necessary evil within enterprises and business running particularly difficult operations to deploy wireless in. We need Wifi mostly for things like barcode scanners and RFID scanners within warehouses. An example of this is a fishery I've worked with where gigantic, grounded metal cages full of fish are moved around refrigerated storage all day long. Another is in a mine shaft where the entire environment is surrounded by iron ore. In these places, wifi is needed, but there's absolutely no reason to run anything newer than Wireless-N except for availability. AC actually costs less than N in most cases today, but there's no practical reason to upgrade. 4x4 MIMO 802.11n is more than good enough in these environments.
5G offers very little to the general consumer. It is a great boon for IoT and for wireless backhaul networks, but for the consumer, 5G will not offer any practical improvements over LTE. 600Mhz 5G is a bit of an exception though. 600Mhz 5G isn't particularly fast... in most cases it's about the same as LTE. It's primary advantage is the range. It will be great for farmers on their tractors. In the past, streaming Netflix or Spotify while plowing the fields has been unrealistic. 5G will likely resolve the issue.
For people within urban environments, they're being told that 5G will give them higher availability and higher bandwidth. What most people don't realize is that running an LTE phone against the new 5G towers will probably provide the exact same experience. 5G will offer far more towers within urban areas and as such, LTE to those towers will work much better than it does to the 4G towers today. 4G is also more than capable of downloading at 10 times higher bandwidths than most users consume today. The core limitation has been the backhaul network. And where 4G typically had 2x10Gb/s fibers to each of 4 towers within an area. 5G will have 2x100Gb/s fibers (as well as a clock sync fiber) to 9 towers within the same area. This will result in much better availability (indoors and out) as well as better bandwidth... and as a bonus, it will improve mobile phone battery life substantially as 4G beamforming along with shorter distances will consume as much as 5 times less power on the phone compared to the current cell network.
5G has no killer app for the consumer. 3G had serious problems across the board since 3G technologies (UMTS, CDMA, etc...) were really just poor evolutions of the classical GSM radio design. LTE was "revolutionary" in its design and mobile data went from "nice toy for rich people" to "ready for consumption by the masses". 5G (which I've been testing for over a year) doesn't offer anything of practical value other than slightly shorter latency which is likely only to be realized by the most hardcore gamers.
I certainly have no intention of upgrading either my phone or my laptop to get better mobile and wireless standards. What I have now hasn't begun to reach the capacity of what they can support today. The newer radios (wifi6 and 5G) will make absolutely no difference in my life.
If you have anyone who listens to you, you should recommend that your IT department focuses on providing wireless network security through a zero-trust model. Which means you could effectively ignore wireless security and as you mentioned, use VPNs or fancy technologies like Microsoft Direct Access to provide secure, inspected, firewalled links for wireless users. They should focus on their cabling infrastructure as well as the addition of extra APs to offer location services for things like fire safety and emergency access. They shouldn't waste money buying new equipment either. Used APs are 1/10th the price. In a zero-trust environment, you really don't need software updates as the 802.11n and 802.11ac standards and equipment are quite stable today. They should simply increase their AP count, improve their cabling so the APs within a building are never cabled into one place (a closet can catch fire), install redundant power to support emergency situations. Use purely plenum rated cabling. Support pseudo-mac assignment to people not carrying wireless devices can be located by signal disturbance during a fire.
Once this system is operational, it should live for the rest of the lifespan of your wifi dependence. I can safely believe that within 5-10 years, most phones from Apple, Samsung, etc... will ship without Wifi as its presence will be entirely redundant.
Also for 5G, inform people that they should wait for a phone that actually gives them something interesting. Spending money on 5G for personal communication devices is just wasteful and worst of all, environmentally damaging. If the market manages to sell 5G as a "killer app", we stand to see over a billion mobile phones disposed of as people upgrade. Consider than even something as small as a telephone, when you make a pile of a billion of them is a disaster for this planet.
5G will be great for IoT and not so much 5G, but the proliferation of NB-IOT is very interesting. $15 or less will provide an eSim capable 5G modem module to things like weather sensors (of which there are already tens of millions out there), radar systems, security systems, etc... We should probably see tens of billions of NB-IOT devices out there within the next few years. A friend of mine has already begun integrating it into a project of hers of which she has funding for over 2 million sensors to be deployed around Europe.
No... you're 100% correct. Wifi has begun it's death knell. It will be irrelevant within 5-10 years and outside of warehouses and similarly radio harsh environment, it is very likely it will be replaced by LTE, NB-IOT and 5G.
And no... 5G on a laptop is almost idiotic if you already have LTE. You should (with the right plan) be able to do 800Mbit/sec or possibly more with LTE. Even when running Windows Update, you probably don't consume more than 40MBit/sec.