Not outright crippled; just strategically neglected compared to the paid variant, unless it’s effectively useless without paying. And then Vercel steps in, buys the whole thing, and Better Auth becomes „Next.js“ first, ideally only fully effective on Vercel.
I would say once a company becomes vc funded, it will have some different priorities.
Although Deno seems to be working out good so far. They are providing value to the general JS eco system. And yes there is Deno deploy, but competent sysadmin and DevOP people will have no trouble running it on their own and scaling.