Yes, no one said find or grep are useless, far from it. The original premise was people using grep to look for a function in a code base, or find to get to a file (presumably to get to an include file or imported module by name). And they are definitely sub optimal for this - as you mention, even outside of an IDE, there are plenty of better tools to integrate with vim or nano or ed (the standard text editor!) or whatever you prefer.

The premise is that using proper code navigation functions will increase productivity over grep. Not that using an IDE will increase productivity over vim, assuming you use actual code navigation tools in vim.

As for the click: all IDEs and all code navigation tools for popular text editors like vim or emacs have full keyboard support. And M-. Or F2 or whatever are much quicker to type than "grep function_name".