If only this was true!

I have a bunch of Makita cordless tools (and IME, Makita was #1 for pros 10-15 years ago, not a niche brand).

Several years ago (2015-ish?) they changed up the battery shape a little bit so newer batteries wouldn't fit on older tools. It was to add another pin so the battery could tell the tool it was dead and quit drawing power (why the battery couldn't just cut power is beyond me). So (at the time) I had a drawer full of year-old tools that wouldn't work with the extra batteries I just bought.

As it turns out, you can file down part of the tool body and the new batteries fit old tools, but without the power protection. So they didn't end up in the landfill, but it's still hugely annoying.