React proper may be more or less stable since hooks came out 6 years ago, on its own it isn't sufficient. You still need to think about react-router, mobx, redux, nextjs, remix, vite, tailwind or mantine or material ui or whatever. And some of these have changed radically from year to year. The react ecosystem is not stable.

It is unavoidable to have a truly gigantic amount of (transitive) dependencies, and its rare you go a month of updates without it breaking your app.

It is true that for backend it is more or less the same, however it is a matter of degree. If frontend is all you do, it may be managable, but for full-stack devs who also need to manage infra it can sometimes be overwhelming.