I have used grep and find for two decades and I could not, last week, remember the last time I typed either of them by hand. At some point rg and fd quietly took over, and I only noticed when I sat down at a fresh box without them and felt the loss.
The honest pitch is not just speed, though searching a large repo with rg instead of grep -r is the difference between a pause and no pause at all. It is the defaults. rg respects .gitignore, skips binary files, and ignores .git without being asked. fd does the same and has an argument order I can actually remember: fd config rather than find . -name '*config*'. The old tools assume you want everything; the new ones assume you want the thing a developer usually wants, and let you opt out.
I keep grep and find installed, obviously. Scripts depend on them, they are everywhere, and POSIX is POSIX. But for the interactive, type-it-and-glance-at-it use that fills my day, I have given up the old muscle memory without regret. The new tools are simply nicer to live with, and after years of resisting on principle I am glad I stopped.