I don't think it's an issue of "pandering" or anything of the sort.
I think it's simply market saturation. Superhero content just isn't that special anymore. It's not an "event". It's not "must see." It's tired, old hat, been-there-done-that material for a lot of audiences.
I've honestly thoroughly enjoyed each of the new TV shows. I liked that Marvel was getting weird with She-Hulk and Werewolf by Night and such. I enjoyed Falcon & Winter Soldier and Loki both, and I really liked Moon Knight, too. But I think that they needed maybe more connective tissue with the old guard of heroes in the new films.
Like, they got rid of Cap, Black Widow, Iron Man, and (mostly) Hulk all in one fell swoop, and Thor's 3rd film was...not quite what people hoped for. And otherwise he's been missing in action.
In addition, while hardcore fans love the interconnectedness, I think a lot of audiences do not like how much "homework" they have to do to follow what the hell is going on. This has always been a criticism of comic books by people who aren't already fans of comic books. Even as a comics fan, it's an issue for me. I enjoyed having big, sprawling storylines that involved multiple characters/teams/titles, but I always hated having to collect 10 different issues per month just to know what the **** was going on. It's a big part of why I stopped buying single issues, and started waiting years to buy TPBs that collect them all for me. I'd bet audiences are doing the same with the Marvel films.
But again, more than that, more than anything else, I think the real issue is that Marvel films...just don't feel that special anymore. You can play at the edges of things by making them less interdependent, making them come out with less frequency, but the bottom line is that when Marvel really hit it big, it was the "new hotness." And now it's just...not. The market is saturated, the audiences are satiated, and they're not CRAVING new stuff the way they did.
Moreover, the actual production approach has, it sounds, become incredibly inefficient and counterproductive. We've had this discussion before, though, right after Dial of Destiny came out and underperformed. (Which everyone now seems to have forgotten about...) Basically, all the studios developed an approach of (1) spending multiple hundreds of millions of dollars in making these films, and (2) actually failing to construct and plan them ahead of time. So much is fixed in post that it sounds like (From the article) it became just "The Way It's Done Here." And that worked great when this stuff was new and interesting and building to a grand finale. But when that ended? The air went out of the balloon, and now you just can't continue to do things "The Way It's Done". You have to do it differently.
Some of that may be smaller budgets, but I'd bet a lot of it is having a longer preproduction window to get clearer on your script, to ensure your VFX team has time to produce good quality work, etc. Back in the day, Star Wars movies came out every 3 years. When the ST was released, they cut a year in production for each of the 3 trilogy films, separating them by only 2 years. For movies this big...well, I think it explains why we get films like TROS which feel very slapped together with duct tape, spit, and chewing gum (if that much, even).
Audiences aren't rejecting this stuff because it's pandering. They're rejecting it because they just don't care that much anymore. They've seen it. And given the pace at which this stuff comes out, if the last one seems kinda meh, whatever, there's another one coming soon anyway. When your films become like busses, you can't expect to do $1B in box office globally.