My cat was a lot like yours currently. I'd let him outside under supervision but he was really unsatisfied being confined to the fenced in yard, and would often hop the fence if we weren't physically stopping him. Toward his last couple years I stopped letting him into the yard at all because he would just run and hop the fence immediately.

What's interesting is that I think his life as a mostly-indoor cat gave him some kind of agoraphobia or something. I knew he wanted to explore so I tried a few times to bring him further outside on a leash or in my arms or just accompanied in general, but he was absolutely freaked out by the wide open space out front. I guess cause the back yard leads to other back yards and to a small access road with a hill on the other side, he'd never really seen anything as far away as the houses across the road out front. And I can't exactly accompany him as he scurries, terrified, under the bushes along the side of the houses. So, yeah, he ended up as an indoor cat.

Anyway, he died of kidney problems at around 15 or so, so idk whether he lived longer than he would've as an outdoor cat. Probably better for the birds though.