Here is my experience:
I am currently 48 years old and have had both knees replaced. The right in August of 2020 and the left in November 2021. Both were troublesome surgeries that have left me with a lot of anxiety and my depression has kicked up a lot also. The first replacement itself wasnt bad, but I got sick with a stomach bacteria from the pain meds.
The second one, I ended up having to have a second surgery because of a malfunction with the device and a catch pin came out.
Lately a lot of my pain is in my back, as I had with the first.
Both surgeries I feel were worse on my mental health and relationships than the replacement of the knees. A lot has happened that I cant get back.
If I had to make this decision again, I dont think I'd do either one. But that is me, with my experience. And I am in no way saying anyone else would have the same experience or even close to it.
I guess my message is more of making sure you know every possible thing you can know. If you have depression and/or anxiety be aware that this can really cause havoc on you!
Best of luck with whatever you choose.