Typos don't really matter in legal complaints, except for looking unprofessional. It would be a waste if my $1000/hour lawyer spent their time proofreading, honestly. The typos also guarantee that I'm getting a real, logical human writing my complaint rather than someone faking it with ChatGPT.
Typos in long-lived documents like contracts, patents, etc. matter quite a bit, by contrast. See eg the second amendment, where billions of dollars have been spent over a few commas.
This is actually one of my favorite uses for contemporary AI technology. It very much can (and does) catch this type of spelling error. Google Docs does this for me quite often. It's not always right -- but it often prompts me to review exactly this type of situation. It's pretty amazing, really.
Typos in long-lived documents like contracts, patents, etc. matter quite a bit, by contrast. See eg the second amendment, where billions of dollars have been spent over a few commas.