Yep, I'm 26. I'm also iterating through different processes to get in as good physical knick as possible, but as you say YMMV. I have hyperflexible joints, which help in racquet sports [dexterity] but make them more injury prone too, for example.
However, putting undue stress on a body is something that will eventually lead to issues. One of my training partners in table tennis is a Doctor who has been practising since the early 80's. He has 3 son's who had reached the top 10 in the country.
Basically one of the important ideas that he confirmed is that repetitive stress/forces from high reps/impact in high level sports will lead to injuries, in months/years/a decade, as eventually your body / muscles / tendons will not be able to support your physicality. That is why supportive insoles are good, all they do is lower impact / increase support, so your body doesn't have to take as much of the impact. This lowers your risk, as well as the magnitude of any injury.
Tennis elbow, knee, back, ankles and now feet injuries are things i desperately want to protect against. I'd rather play at 99% for the next 30-40 years, rather than play at 101% by playing in the lightest shoes around for a decade, then at 50-60% for the next 25-30 years. As a non-professional, you can recover than 2% through improved technique / conditioning, whereas for a pro the tradeoff may be worth it.
