Asklemmy

It's not quite what you're talking about because they're still brand-specific, but the batteries are a big part of why I went with Ryobi. They've done a really good job of sticking with their battery ecosystem IMO, and it's now kind of a big part of their marketing so I think they're going to stick with it for a while, at least for their regular 18v hand tools. If I ever come across some old blue Ryobi tools at a yard sale they should work just fine with the lithium batteries even though they were designed for NiCad batteries, and I'm pretty sure you can still get a dual chemistry charger that works for both kinds of battery.

I'm pretty sure that in the same time Ryobi has been around using using essentially the same batteries most of the big names are on their 2nd or 3rd battery standard.

Admittedly they haven't been perfect, they've done pretty well sticking with their 18v and 40v lines, but I think they've had a couple different standards for smaller, lower-powered tools that have come and gone, although I like what they've been doing with their newer USB lithium line so I hope that sticks around. I think they also had a riding mower battery that was only around for a couple years before they replaced it with a new incomparable one.

And I'm very much a DIY homeowner weekend warrior type, if I used my tools professionally I don't know that I'd want to depend on Ryobi, but they're more than adequate for what I need them for.