Totally sensible decision and I'd never suggest switching engines, but I do have to say you're missing out on a lot on MZ!
IMO it's a choice between keeping your perfectly well rounded setup that you've already developed on MV (and I know you have a great grip on MV since you've been working on it for years) vs. MZ's SEVEN(!) major updates plus the absolutely crunchy plugin database. Just... Making Action Sequences with the (free!) Visustella Battle Core is soooo much better than notetags on MV, for example -- using both Common Events AND the refurbished Plugin Commands command (lol) is the perfect illustration of MZ's improvements.
But if you already have your MV setup ready, then you can streamline those MV battle sequence stuffs pretty alright.
I just, I can't read a comment like "the improvements don't justify the cost" and not give my 5 cents given the absolute massive list of updates and new stuff it got. I can do so much stuff on MZ, going back to MV kinda gives me the chills tbh 😭