I changed from a OnePlus 6t to a Samsung S23+ after about 4 years of using the old one and at least for me the difference is huge. Both are flagships in their own time. The oneplus was starting to feel a bit laggy here and there, but I never expected the S23+ to be all around so snappy in comparison. Camera quality is leagues ahead. The battery life is way better. The fingerprint sensor was never good on the oneplus, but it's amazing on the Samsung. There are many other features I like or find useful like the wireless charging or the water resistance. The new phone is an all around better package for me and a surprisingly decent upgrade.
You definitely don't need to upgrade every 2 years and it probably matters what you expect out of a phone and how patient you are with the issues, but I think new phones do still offer compelling reasons to upgrade, just not as often as in the past.
Congrats on the most ignorant comment on this side of the server. Not only did you achieve this once, you continued to show your ignorance in a whole thread of discussion. Incredible.