Context: I'm going to be turning 65 in May. I started playing RPGs with OD&D in 1975. Over the years from that, during the early days I was involved with multiple gaming groups and clubs on the West Coast in one fashion or another, and went to conventions regularly until, I want to say 1995. I was also continuously involved in multiple APAs (amateur press association zines, the closest thing to fora or mailing lists in those periods, which were produced by people in various areas and their contribution mailed (usually; some zines you could simply type your zine and mail it in, paying the collator to do the printing for you, which I did most of the time because getting things printed locally was tricky); the most well known one I was involved in was Alarums and Excursions, but also less well known ones such as Rogue's Gallery and The Lord's of Chaos), later on mailing lists, then yet later USENET's RPG related groups, fora once they came along, and now various Discords.
I cannot think of a single one of those venues where I did not hear people complaining about entitled players, GM's with God complexes, or both (early on this was so damn common it began to set me on the road to conclude that the GM-authority model had serious problems right out the gate, something that has not decreased over time). Sometimes early on it might not be framed as "entitled", but just "bad", because it was taken as such a given that challenging the GM about, well, anything was intrinsically bad behavior. If I was to estimate how many times I'd seen this complaint over the years, I'd suggest the minimum case lands in the hundreds (it had exceeded a hundred probably back in the three years I was involved with OD&D proper, just from comments at conventions, in the APAs, and in the game clubs I participated in (one relatively small, but one middlin' large). Once you started including the digital communication, this blossomed over time such that if you told me it was in multiple thousands, I would not be noticeably surprised. There's been some change in framing over the years, but the fundamentals of the complaints have not changed much; GMs claiming players have unreasonable expectations.
Now, does this mean the complaints are never unwarranted? No. Sometimes its GMs on a power trip, sometimes its players with tunnel vision about their specific wants compared to the overall health of the game and/or how those wants impact other players' equally valid wants, sometimes both at once or some middle case.
But the point is: this is not new. As was suggested earlier, if it appears new that is most likely a consequence of D&D5e having brought in a large surge of new blood, unlike the OD&D and AD&D days (where most people coming in were either wargamers or SF fans (who often had some limited experience with freeform RP even back then--you could see some of it coming up in Star Trek and Pern fandom even then), or the D&D3e days (where you got some non-trivial returnees who had left D&D for other games but were willing to return to see how this significant change impacted the game experience), these people are new. Their expectations are set by things that are not always congruent with how the play experience works. I can see how this can make it seem like there's a massive surge here, because even a modest one can easily stand out, especially if one encounters a number of people dealing with mostly new players entering the hobby.
But attempts to claim this is somehow intrinsic to 5e just falls kind of flat. I've looked at 5e; I'm not a fan. But there's nothing I see there that would make anything the game brings to the table create more problems in this area than 3e did, and even that looks dubious given how many of these complaints I saw and then later read about D&D players across the OD&D through AD&D2e--extensively--across literally decades--its a hard sell. Even moreso since I've also seen it about any number of other games over the years.
Does the above make it more clear why my position on this is cynical? I might even buy there's a (modest) increase in problems here in the D&D sphere, simply because more new blood has entered there in the last few years, and that's going to stand out. But its the cause-and-effect I really turn a jaundiced eye to, because the complaints seem much the same--and there were plenty of them--over the decades.