I get that this might annoy you, but there is a direct trace all the way back to the original Mac in 1984 that required a mouse. As time went on and the two other OSes we still have gained mouse support (Windows, Linux) from their keyboard roots, they brought forward their ethos of keyboard navigation. Mac OS resolutely stayed attached to its mouse only roots.

I’m annoyed that this isn’t the default.

I really feel like this used to be the default. That's how I always did it in macOS going back to the early 2000's.

Only in the last two versions or so did I notice it was no longer the default. I'm glad to see here that I can now re-enable it.

Edit: I see that I do have it enabled. But for some reason there are a lot of programs where it doesn't seem to work anymore, no matter what the settings. Off the top of my head: Half the Adobe programs I use for work.