What if the generator rolled a 4 though?

first, what if i have my cat do it. second, why does it matter if a string is maximally random? is there a certain level that is random enough?

Generators aren't intrinsically random either, the project that's closest to random is the lava light room at cloud flare. But a wall of lamalamps aren't random enough, so they add in a few parameters from the moon.

But ultimately, it's not truly random.

Most generators are magnitudes simpler than that and honestly mashing everything at random yourself does a pretty good job at it. Especially if you smash too many characters and then scrambles it before picking a sequence without thought. As the biggest issue with manual button smashing, is the same character either won't appear twice in a row ever or will always appear multiple in a row. Not to talk about special letters, which you likely wouldn't hit - although we could make larger keyboards for the lulz

Ultimately random generators is just a simpler/faster solution, but there's ways of doing something as randomly by hand