I have had two knee replacements. In spite of weighing more than I should, I was back to hiking at 10K feet in the Sierras about 10 weeks after each surgery. Crawling or kneeling are no longer good, which makes gardening a different experience than it used to be.
RV steps are not a problem for me. I am careful to use the assist handle.
Possibly the best after-effect of the 2 TKR's: no more knee pain. Yay! After years of it.