I've watched this guys small channel for a while, as I was thinking about the MG, but I think I've changed my mind...
Having just picked up my MG4 last week I'm probably a bit biased but my take on that video is it shows 2 underlying (and very valid) issues.
First is that the early models had issues, most of his seem to be those really, that's not a great defence of MG here as those issues are unacceptable and in the same position I'd probably be thinking the same really, but it's also not a problem completely isolated to MG.
Secondly, and probably the bigger issue to most buyers, is the dealer network. I believe all MG dealers are just franchise and there are some bad ones, maybe because it's a 'budget' brand so the dealerships don't want to put any money or effort into support or maybe some dealers are just bad, again not really MG specific, but when you combine this and the early car issues the experience can be utterly awful.
For me I've only dealt with the sales side of the dealership, and that was fine, and currently no issues at all with the car so hopefully I won't encounter the service department until next year, but we'll see.
One side note, and really not trying to target him specifically, but he seemed to jump through hoops to get the MG4 early, he mentioned going 2.5 hours to pick it up (and immediately encountering the terrible dealer with the dents :/) but why do people do that? It's a bog standard cheapo mid-size hatchback, with a fairly wide ranging dealer network (I've got 3 dealers within ~40 minutes drive, I picked the on 10 mins away), why be in such a rush to get it that you're travelling half way across the country to do so and ensuring your 'primary' dealer is so far away? Not that his local dealer was really any better it seems...
I guess also it's hard to judge a company based on on customers experience, or even a few as several of his problems were occuring across several owners cars, if we did we'd all discount Tesla because they don't install brake pads, or Mercedes because their ABS pumps fail, or <insert other car issue here>