But that's not what happened. Most films are either new stand-alone films with some connective bits at the end, or they're direct sequel films that assume you've see the previous films within that franchise, but also fill you in.
The two biggest films were actually the most interconnected. Spider-Man No Way Home is full of Spider-Man references not just in the MCU, but to the previous Spider-Man films. Deadpool & Wolverine is full of X-Men and Marvel films pre-MCU references. Both of these films are highly rated and made a shit ton of money.
But are there a number of mid tier films released? Absolutely. But it has nothing to do with required viewing.