This is a conclusion lacking in support.
While I can see where the general sentiment might originate -- a glance at pop culture could suggest everything truly is being pulled into an inescapable black hole of the same things controlled by the same people, spiraling into the the creation of a media singularity and the heat death of all culture -- reality is a touch more nuanced.
There is endless new media unconnected to any of this franchising: while much of this deserves to be appreciated by a larger audience, even celebrated, it does unfortunately tend to lack the same media push and marketing benefit which larger franchises appreciate, but this doesn't mean everything created in one of these franchises is bad. There's no actual logical connection there.
It can definitely seem that way sometimes, of course, given the oft-apparent need to churn out new content to keep a franchise relevant or for some misguided ploy to amass greater profit, all of which can lead to a deluge of dross, but it still doesn't reach the decisiveness displayed.
And sometimes an existing universe can be leveraged, with built-in themes and intertextuality, history, motifs, and images that can be used as shorthand to support the larger intent, and so forth (I've
very briefly mentioned Andor's use of series' iconography and history[1] before as well as what I see as
The Mandalorian's failure to effectively use thematic support readily available to it[2]). These could theoretically be reworked for something to exist outside the universe in question, but not necessarily always to such economical effect, and removing a story from one of these universes won't necessarily improve it, except, maybe, for one's own estimation of the project.
What about removing a story from an established universe would always lead to its betterment?
How does the idea of this media singularity necessarily mean an individual project must be bad, entirely divorced from any details about the piece of media itself?
In conclusion, I don't really award marks for internet hot takes, and your conclusion calls for support it hasn't been given.