There’s realistically no reason not to generate the max password. The different in possibilities between a password with 16 characters and one with 20 (using a-zA-Z0-9!@#$%^&*()?-+." which isn’t even all the options) is 1.2E30 v s 4.13E37. That’s seven orders of magnitude from 4 characters. The difference between $1 and $10,000,000. But to be fair, 1.2E30 possible combinations is kind of a lot already, but why not add a few more characters just for the hell of it?
There’s realistically no reason not to generate the max password. The different in possibilities between a password with 16 characters and one with 20 (using a-zA-Z0-9!@#$%^&*()?-+." which isn’t even all the options) is 1.2E30 v s 4.13E37. That’s seven orders of magnitude from 4 characters. The difference between $1 and $10,000,000. But to be fair, 1.2E30 possible combinations is kind of a lot already, but why not add a few more characters just for the hell of it?
If you always use the maximum then the length of your password becomes predictable which reduces the number of permutations.
It’s probably better to use a password of around 60-100% of the maximum