Me to, but to be fair, I think this is no longer unique to Emacs. See for example the "command palette" in VSCode; it isn’t "tab completion" per se but similar to e.g. M-x with Vertico.
I was thinking I was crazy...I use command completion in lots of different applications...
Probably he's referring to "fuzzy find"?
Yes, VSCode has something similar, I believe. But Emacs had it before VSCode existed ;-)