Although there are a ton of alternatives out there they are all "too hard" or something, so since Zoom mostly works OK most of the time and is dead simple to use it will continue to win out over everything else.
My position on Zoom hasn't changed since 2020: Anyone using Zoom will continue to get exactly what they deserve.
1) Until recently, Zoom's video/audio quality knocked everyone else's into a cocked hat. I don't think that's the case, anymore. Looks like a lot of folks got off their butts, and improved their quality, but I haven't seen this mentioned anywhere, by anyone.
2) Everyone else is using it.
#2 is a biggie. Monopoly inertia is pretty hard to overcome, for people not in the tech industry (we'll change on a whim).
Zoom is not easy to use. Its settings are a mess, but everyone is used to dealing with the Zoom pain, and don't want to switch.
We can be remarkably cavalier in dismissing non-tech folks, but I learned to stop doing that, many years ago. We're not the only smart people in the world.
People (in general) don't like getting sidetracked by their tools. They want to get a job done, and how they get it done is not irrelevant, but not that important to them. They develop and refine a workflow, which is usually heavily informed by their choice of tools, and that "wears a groove." They don't want to switch grooves; even if they are not enjoying their tool.
Most tech folks, on the other hand love tools. I had an employee that would stop his main project, and design a massive subsystem, just to make a simple command-line process a few seconds shorter. I had to keep on my toes. He was the best engineer I've ever worked with, but it was a chore to keep him focused.
Non-tech types are seldom like that, and we can sometimes miss it.
These are the folks that use our products, and we don't actually gain anything by disrespecting them, even when they really piss us off.
TL;DR: Want people to stop using Zoom? Produce something better, and make it something that non-tech folks will love.
That means easy to use, forget-about-it UX, and extremely high quality.
Or you inherently can't make it "forget about it UX and extremely high quality" as most non techies define it. Because you have the issue that even if a company self hosts a meeting tool, they likely can't get the backbone connections Zoom etc can get. They at least need someone to use a URL to get there. It can be made mostly simple, but then you're back to some company running it - works for corporate use maybe, not for your home user. Even Signal lags compared to Zoom. And people really dislike Signal's phone number requirement, but it's what makes it somewhat possible to route connections for users.
What's a system that a home person could use that's not going to get them routing through one companies servers, but is actually simple enough to use?
The place where I do get somewhat exasperated as a techie is that the equivalent of asking for a phone number or address in any program that isn't an e-mail website is seen as "too hard". This makes pretty much any privacy respecting design impossible to scale beyond nerds.