Don't be! 6S is awesome phone - in fact, beginning of this year I was still rocking my iPhone 6 (which is now my backup/holiday phone). I switched to iPhone SE 2020 and I couldn't be happier. Sure, there is not much difference apart from speed but the pictures it makes compared to my 6 are just stunning.
You feel the right thing and I'm in the same boat. It comes with age and maturity as after 30 I feel that we tend to stop chasing the latest and greatest and we re-prioritise our live and we get to conclusion what is and isn't important.
At the end of the day, we just want to get stuff done and we want the right tool. It doesn't matter if iPhone 12 is 10x faster than iPhone 7 or whatever if the task you do is the same. iPhones reached that level and there is literally zero incentive to get a new one regardless what someone tells you. Be happy that you have reached this stage as that is a good sign.
Funnily enough, Apple is chasing the iPhones speed where it makes zero difference to us and yet the Macs that benefit from speed are neglected. iMac is prime example where they have neglected the speed.
Its a jet engine starting with insane temperature to get the job done and its still slow.
It drives me crazy that until now, Apple simply didn't care enough!
I really hope AS will change that as its time for Apple to chase the speed etc. on the products that it really matters!
iPads and iPhones can play current games at the highest settings and be super fluid and yet, the same can't be said about their Mac line. In fact, I would dare to say that the Mac Pro can show intensive current games at ultra settings on the XDR screen.
Same goes for other things.
Anyway, I have high expectations from AS because I feel that it will allow me to try different products from Apple that were not sufficient enough (ie. the Mac Mini). We shall see but the future looks great