Most people aren't Shakespeare and could use a bit of help with content writing. There are many different browser & CMS add-ons that can help like Grammarly. Not having typos and correctly using commas will make a better impression on users which can indirectly boost many key metrics.

Before you rush off and implement this on your entire site, remember that Google tends to reward freshly updated content. What's the worry, sounds like a bigger reason to do this? Well because Google knows that we know this, they also penalize sites that abuse it. Years ago, webmasters realized that if they ran a script to make a super minor change to every article at the start of each month, they would get a ranking boost. So Google evolved to block that trick. If you add a grammar checker to your CMS and touch all your articles with super minor changes you might accidentally look like you are trying to spam the freshness booster. Safest to slowly phase it in.

Remember that part of ranking well in Google means knowing how to avoid accidentally triggering a false positive on their spam filters.