Personally, I always feel like these timeline arguments are little more than inventing new reasons not to like something. Perfectly fine to not like something, of course, but it starts to become a stretch when people start nitpicking because they feel like they need to justify their disdain or start telling people differing opinions are wrong.
Maybe it WOULD have been better to set Discovery in a different timeline considering they pretty much had to tech up a bit to avoid alienating modern audiences, but they didn't so it is what it is. Really, aside from the make-up thing there's not really much there that's super egregious.
Speaking of Discovery, I had a thought recently: in season 1 everyone was accusing Burham of being a Mary Sue, and I never thought that was the case. She was for sure a sole protagonist in an ensemble work, but as much as she got blamed for everything, events didn't really revolve around here. The irony is in Season 2 where they pulled back to give other characters time to shine, they MASSIVELY upped her sueness by making her the central macguffin. The universe doesn't just rovolve around her, time itself does now. Still enjoyed it more than Season 1, but damn.
I've also gone back and started a full rewatch of TNG in its entirety (i've watched full seasons before, but never the entire series, and I usually gave the first season a skip) and I am really struggling to get through the first couple of seasons. They are so inconsistent with episodes so terrible it's actively giving me viewer fatigue where I have to take a break every few episodes. I knew the first couple seasons were bad but I didn't realize they were this bad. This may actually be the worst Star trek has to offer. The other series had pretty rocky starts too, but I remember them being more mediocre than downright terrible even if Enterprise and Voyager tended to get pretty dumb throughout their runs and were worse overall than TNG.