We aren’t talking professional sports, my experience is 100% of those I know being able to do anything they want to do, my MIL had double replacement at 85 yo and you would be hard pressed to keep up with her now that she is 90!From what I've seen, the percentage of people who have had their knees fixed, and are pain free and mobile is less than half.
Spend your money on an electric wheelchair, since the odds of needing it a year after the OP are pretty good.
If your surgeon is really world class, and you physiotherapist has been treating the US Olympic Team for years, have the OP done, otherwise take 3 steps back, go directly to jail without passing go and rethink.
Michael