I have a MacBook from 2017 and and m3 air today.
For day to day tasks there is no difference.
For developers, the difference is like night and day.
My 2019 MacBook Pro used to sound like a jet plane taking off whenever I did any sort of build. On a bad day, I could've baked some cookies on it. Admittedly, the corporate spyware that was constantly scanning every single file didn't help matters.
Try using it unplugged.
Eerily similar story here. My wife was using her 2017 MBP (the one they got sued over) and she adored it until Tahoe suddenly caused Chrome to run like hot garbage. I bought her an open-box M3 Air. She likes the color. It doesn't provide any more value to her life than her 2017 MBP did, and yet we're out $1000 because Apple said so.
I have a MacBook Pro from 2016 and an M4 Pro from last year. There is a night and day difference.
I think "M series chips are no better than ten year old Intel chips" is a take that would be somewhat difficult to sustain, given the data.