You can point to the decline of most of the industry (not just Disney) on these two things:
1. Steaming in many ways killed a lot of incentive for studios to take risks. DVD sales used to make a huge bulk of a film's income. On top of that, the younger generations prefer to watch everything on their phones. YouTubers and Streamers are the new celebrities. Because of all this, films have suffered in terms of selling tickets and DVDs. Yes we still have blockbusters that make a lot of money in theaters, but the vast majority of them are part of franchises like the MCU. Films that are safe, and where studios feel comfortable throwing $300 million dollars at. Films like Top Gun: Marverick are an anomaly because every once in a while you get a talented filmmaker or actor who has a passion project they wanna do, and happens to have the right pull to make it happen.
2. The rampant problem with nepotism and far left politics being deeply embedded in Hollywood culture. Hollywood looks after their own, so long as you play the game. People who try to make it in the business and don't conform to that ideology, get far less support and opportunity. To be clear, I'm not saying left winged ideology is a bad thing. The problem is the wrong kind of people are being hired for the wrong reasons. Instead of looking for the best talent out there, they're looking to diversify their brand as much as possible, hiring people who share the same political views, and want to use film/television as a platform to push their agenda. That is why most big tentpole films, especially from Disney, seem to have representation of every corner out there. It's why every Disney female character is a flawless and good at everything, because they have bad writers who have a fundamental misunderstanding on what makes a character relatable and powerful. This kind of culture that has sunk it's flaws into the industry is detrimental to creativity.
Both of these reasons are why big studios like Disney are a creative voids these days. Because studios no longer want to take risks, they aim to appease the masses, and toxic workplace culture.