if you actually look at % of impacted clients, it’s tiny.
meanwhile, it is very unclear that any sidechannel attack on a libolm based client is practical over the network (which is why we didn’t fix this years ago). After all, the limited primitives are commented on in the readme and https://github.com/matrix-org/olm/issues/3 since day 1.
Most big providers end up being cheaper for you as well. Vercel is insanely expensive.
If you're trying to make the argument that because they can be insecure, we should not use JWTs. Thats not really a great argument for most people. JWTs provide a lot of value, and the idea of having some secure, validatable, and no network required check for authentication, or transporting information. Is too valuable for businesses. So we all use JWTs, they are a decent standard.
At the very least you should propose an alternative that people use besides JWTs if you're going to vaugly hand wave about the scary security issues of 2021 firebase, and 2020 Npm packages reported by Auth0.