> My experience with MobX and the greater observable-industrial-signal-complex is that accidental loopiness very much can and does still happen. I have seen codebases with complex MobX computed-changes-graphs that senior engineers were clever enough to write but not to debug. And I was not aware of tooling which helped keep these graphs in line.

My experience is completely the opposite. I've worked on large, complex interactive editors writtein in MobX and its been pleasently easy to reason about. Some tooling is built into the framework (cycle detection, strict mode). The design guides you towards making the right choices (prefer computed over autorun, etc) and makes those choices easy to use.

And unfortunately, with useState, useMemo and useEffect you can make the same cyclic dependency spaghetti (e.g. useEffect can easily setState). Unlike with MobX however, everything is harder.