I’m 43 and just had a left THR in October. It’s a ceramic/plastic and was done through the anterior approach. I had all the same thoughts and concerns that you did and even experienced notable improvements for two months leading to the surgery. I think that was because I really started focusing on overall fitness and nutrition to prepare for the surgery.
I will tell you that I don’t regret getting it done at all. I Didnt have a lot of pain but the mobility I lost was really starting to wear on me. I ride dirt bikes and couldn’t even get on or off the bike without pain or even falling over. I’m still recovering but I’m back to being active again. Running is taking a while to get back up to speed but I think that’s due to muscles shrinking from the 3 years that I suffered. (At least that’s what the therapist says)
I’m only 4 months post op and the improvements are amazing. I almost have full mobility and strength back, more energy and no arthritis pain. As far as the psychological part I struggled with that too. Will it wear out, will it break if I crash my bike? You name it and I thought of it. My doctor assured me that if I stay healthy and active I should be fine. Might last 20 years might last 50, everyone will be different. He said if I wear it out and they catch it early he can do a simple revision as the new hip is modular. Also said to live my life and do what I want. No real benefit to squeezing a year or two out of your original equipment at the expense of quality of life. Good luck and keep us posted.