Quoted from HoakyPoaky:

IMO Marvel is striking out in Phase 4, and it not as noticeable because it's easy to blame the pandemic for average grosses. The Infinity War story was peak storytelling. IDK if they'll ever be able to reach those high grosses again. Phase 4 is basically filler & backstory, while pushing some pretty lousy C & D list Tier characters. They caught lightning with the little-known Guardians, and they seem to think they can turn any character to an A-lister in the MCU.
They have an agenda in this phase. Prioritize inclusion and female characters/directors, while expanding the brand worldwide & reaching a wider audience via streaming. IDK how that's working out so far.
Black Widow & Eternals are Bottom 5 MCU movies. Really boring stories with uninteresting characters. Those movies are downright unwatchable. Shang-Chi was pretty lousy too, with bad attempts at comedy & pretty noticeable poor CGI. None of these demand repeat viewings or sequels. You felt like you HAD to see the next MCU movie or you might miss out on something. These Phase 4 films don't generate that excitement at all.
People just want more Spider-Man, Dr Strange, Guardians, Thor, etc. Things will pick up when those sequels are released. Think people will be lining up in masses for $3B grosses to see Ms Marvel, She-Hulk, Shang-Chi, Ironheart, Moon Night & Blade take over the Avengers? I seriously doubt it. Ironman, Cap & Black Panther are dead. Fans really just want to see Marvel's take on the X-Men/FF in Phase 5. It's fodder & filler for another 3 years until then.
That said Loki show has been the most enjoyable so far. The Hawkeye show is based on a critically praised comic book run from a few years back. The multiverse story has huge implications moving forward, and Kang the Conquer will be a pretty good baddie until Doctor Doom, Magneto, Silver Surfer & Galactus come along.