There used to be a Firefox extension called FLST (Focus Last Selected Tab) that solved this problem, but that was years ago and I've yet to find a suitable replacement, ever since Mozilla rolled out web extensions and severely limited how much they could modify the browser.
I miss the early days of Firefox. It was a lot more fun.
BTW: Use the new Tab Groups feature if you haven't already. That way you can still have 100 tabs open while still keeping your browser neat and organized.
Back in the early days of modern smartphones it was "find my Android". Regardless, either search will still get you where you need to be today. (That is unless of course you've degoogled.)
Cats can also handle a harness and a leash a lot better than you think, especially the friendly, outgoing cats. Just don't expect them to be able to keep up with you like a dog. Cats move at their own pace and will protest if you try to force them to go with you. Let them lead the way, and expect to spend a lot of time standing around in one spot.
Basically what I'm saying is that leashes work best if you're not in a hurry to go anywhere in particular. Backpack if you are.
I feel that. I'm also nowhere near Florida, and don't have the spare cash for an airplane ticket right now. I'm making $19/hr and I can't even afford groceries.
Maybe I should start licking batteries, then. I had no idea they tasted so delicious.