How do you decide which new tools are worth keeping?

Every week brings new launches, and I try a lot more tools than I keep. My filter is simple: does it replace something I already use, and do I still open it after two weeks?

For example, I tried three different note-taking apps this year. Two were beautiful but I stopped opening them after a few days. The one I kept looked plain, but it saved me time every single day.

It made me wonder if my filter is too strict, because the “boring” tool beat the flashy ones.

How do you decide what stays in your stack? Have you ever kept a tool that failed your usual test?