TBH, having a tool like that would change things for the better. Imagine a spell checker with a scoring threshold—let’s say 70%—that you need to hit before posting. It wouldn’t just help filter spam and low-effort posts but could actually help people learn, especially if it includes grammar tips. It would encourage folks to slow down and focus on their writing instead of just rushing to post anything.
How would that reduce spam? We are talking about a score that checks mistakes in what is written and not the length of the post. If I write, "I love this forum from the bottom of my heart.", I will still get a good score for it because it's grammatically correct and doesn't have spelling mistakes, but that doesn't mean this is a great post and I'm not spamming.
A system like this won't help reduce spam, it will only reduce posts written in a way that isn't easily understandable, and I don't think it's required at all. If you understand a post, and you think it makes sense, well and good, and if you think the opposite, you can report it to moderators and they will take care of the rest. Restricting people from posting on the global boards will only bring more damage to the forum because there are a lot of users who might not be able to write English fluently but we can still get what they say and a post's quality doesn't only depend on that, in my opinion.
P.S.: You need to learn to check the dates of the latest posts done in a thread before writing a post because you have just bumped an inactive thread from 2022 which was completely unnecessary.