I held out on this for a long time. grep and find have been in my fingers since before some of my colleagues were writing code, and "it's faster" has never once been enough to make me relearn a tool. But ripgrep and fd have crept in anyway, and I've stopped fighting it.
The speed is real, rg tearing through a large repo in a fraction of a second is genuinely lovely, but that's not why they stuck. They stuck because the sensible thing is the default. rg respects .gitignore without being asked, so I'm never again searching through node_modules and a thousand build artefacts by accident. fd foo finds files matching foo without the find . -name '*foo*' -type f incantation I've typed ten thousand times.
What surprised me is how much the friction mattered. The old commands weren't slow to run so much as slow to write, and that tiny cost meant I searched less than I should have. Now I search constantly, because it costs nothing. The tool got out of the way and changed the habit.
I still know the old flags, and on a server I don't control I'll happily fall back to grep -rn. But on my own machines, the muscle memory has moved on. Took me about five years longer than everyone else, which feels about right.