Hopefully 7 years from now you'll still be able to use it with modern apps, websites, and video content. IMO, The benefits of these chips are in longevity rather than pushing them to the limit today.
This is the pretty obvious answer. I'm looking at replacing my gen-3 iPad Air from 2019 because it's feeling pretty pokey now. (And my wife's gen-1 iPad Air from 2013 is entirely unusable.)
I don't think there's any amount of processing power that can keep up with website bloat long term, but you out to get an extra year or two from the M3
