I don't think it's bad for 'competitive' typing but it's nothing like the real process where fixing mistakes at the end is almost a triviality instead of completely derailing your typing.
For most people, that involves relying on another service ("look to see what words have a red squiggly line under them").
It is not a good way to measure "typing speed".
That seems optimistic, odds are your typing flow will be interrupted as tou think about the mistake and go around to fix it, plus you likely only realise it a bit later and need either some movement or to remove entire words and retype them.