Yes, surely upgrade is always helpful as it intent to provide new features, remove existing but and enhance security. But what is the use of it, if your device doesn’t provide basic service. To give you some example below are the issues that I faced.
1) My iPhone XR after upgrade started giving problem with touchscreen, none of its keys on left side were working
2) Current problem, my I watch series 6, now don’t respond to horizontal swipe and it hide date as if it is secret code and only visible when I touch it
And there is at least one issues with each upgrade.
And Apple support person not ready to accept this is fault and they have responsibility to fix it.