Short answer is yes. Longer answer is, it has been more of a shift than and improvement or great loss. So when I started I had much better fitness, movement, eyesight/proprioception, and no vertigo. Strokes were not very clean or technically sound, but I could compensate with the fore-mentioned attributes. So I could compete, at best, as a 50/50 4.0, but more just moving between low 4.0 and high 3.5 depending on year and life balance. As I got older and I had more years under belt my strokes improved, court awareness/IQ went up, and consistency leveled up, but fitness, eyesight, and movement dropped a bit. Along with that, more reoccurring injuries and issues. I dropped down to a middling 3.5 for a few years, but also had more life to deal with and less tennis time.
Few years back I started getting back in shape, getting more court time, and focusing more on managing how much I move, picking when to move, and using consistency and placement with a wider range of shots compared to my younger self. Still just playing high 3.5, but started getting wins in 4.0 again. So still have a solid serve, but not that 100+ mph, but more on placement to set up plays. More variety of shots using all court style play instead of more baseline bashing. I like to come in and close at net more and am more comfortable doing so. I am apt to try to end points quicker, but also have developed a better neutral ball that can be more offensive. I enjoy strategy or figuring out the opponents weakness and trying to exploit them over just hitting hard where they aren't. Things llke that. Agaiin, more that I am conscious of those things than really great at them.
So today at 52, again there hasn't been any great level-up, but I have been able to maintain my better efforts while managing some of those "getting older" issues that might drag people down. So can't complain too much, but it does get a bit frustrating when you know you used to be able to do something that you can't anymore.
That said, more of the issues are on me given my penchant for good beer, drinks and food in lieu of better fitness. So I see plenty of high level players in their +50 years and know I could compete up if I was more dedicated as many of them are.
Overall, it is just managing my body more.