Azure vs AWS
For what it's worth, in my unscientific view it seems that developers opt for AWS (PaaS) whilst infrastructure geeks opt for Azure (IaaS and SaaS).
I'm the chief geek for a mid sized MSP (circa 90 clients).
MS have a "story" with hybrid (I hate myself for using that term), and can be so very easy to use for even a small thing like as a file share witness in a cluster (great if you have a single site), as well as a massive hook with Office 365 and licensing. Amazon have development nailed from what my dev department tells me. They tell me that Azure is about 85% feature comparable to AWS with them both being equally easy to use.
Literally heard nothing about Google Cloud or others outside of the odd SaaS service (Salesforce, one Oracle for a cloudy CRM etc).
Two horse race, and personally I think it shows the true value of healthy competition. We have at least two very, very good cloud providers to use that continuously try to keep up with each other. I'm no economist, but this looks and feels to me like a textbook example of free market capitalism at work.
All of that said, I still would rather have business critical infrastructure hosted in a date center we can access on tin that we own. I'm enormously proud that multiple HA Exchange and SfB environments I've designed and implemented over the past 3.5 years have 100% uptime which beats Office 365.