Earlier quoted context omitted.
>and then you upgrade to a faster unit with next-gen wifi or whatever Do people actually need next-gen wifi? My impression is that 99.9+% of people would be well served by a mid-range 802.11ac router (eg. AC1750[1]) from years ago, because the most bandwidth intensive thing they do is watch 4k netflix (~25 Mb/s). [1] https://en.wikipedia.org/wiki/IEEE_802.11ac-2013
I'm sure people said the same thing about 802.11ac when everyone was on n, or n when everyone was on g. Faster is always better. New 802.11ax also improves contention between devices.
For wifi faster isn't always better if there's nowhere to go. That is, if the uplink from home isn't itself faster.