That statement above is of such higher quality in terms of English proficiency than your posts from back in 2017 that I have to wonder if you're either already using some kind of AI tool to polish your shortcomings OR you somehow got your hands on this account which used to belong to someone else.
A third possibility is that you've improved your English, but I don't think I've ever seen that happen with an account that's recently woken up from a long break.
The fourth possibility, and to my mind the most likely, is that he is using an automatic translator such as Deepl.com. The level of reliability is very high nowadays and they are used massively on and off the forum. He doesn't break any rules if he does that as far as I know.
That's crazy. Why would I use a translator if I can write in English? Your suspicion is entirely baseless.
Grammarly, like the other members suggest would help you in grammar.
So AI tool can't be use to function like Grammarly?