My cat is indoors only and made a couple escape attempts that were a little traumatizing for me (helicopter cat mom here), so while I considered getting him a leash once, I ultimately decided against it because I was afraid it'd make him a little more comfortable with the outside world and might emboldened him to make more escape attempts in the future. Not happening in a rural place where there's coyotes, oh hell no.

So instead of walks, we play catch. I wad up paper scraps and throw them and he'll leap into the air to catch them with his paws or swat them away. His ability to catch is honestly amazing to me, he gets it the vast majority of the time, and sometimes he'll leap a good 3 feet in the air, it's super impressive. It's also extremely entertaining! I have a lot of fun with "cat baseball practice", and I think the reason he's so responsive to paper wads is because those were the only cat toys I had for him as a kitten, so every time he hears the sound of paper crumpling he perks up and comes running.

He also loves diving into 12 pack cardboard boxes with the ends ripped off to make them into a tube. My living room floor is constantly covered in trash cat toys but I love it.