Fixed wireless is the "killer app" for 5G. There isn't much point to it on phones, where LTE is already more than fast enough. There isn't any use case for going faster than what LTE is capable of on a phone. It lowers latency, which may matter for gamers but how many people are doing latency sensitive gaming via cellular instead of wifi?
I just bought a new iPhone. I could have waited until next year and got one that included 5G but that didn't even factor into my purchase decision. I'll keep this one for 2-3 years, and eventually will have 5G in that next one - but only in the sense that I have 802.11ax/wifi6 on the phone I just bought. It is there, but wasn't a factor in my purchase and it'll probably be a good long while before I connect to any 802.11ax networks and when I do I won't notice the difference.