Clojure is like that, but because data structures are default immutable, and all of the standard library (and the vast majority of 3rd party libraries) are also default immutable, the stress level is much lower.

You can still get mutability and I do this on every project. But it's a very small percentage of the code, less that 1%, and also well-defined.

Something like FlowStorm [0] isn't really practical in anything but Clojure, and things like Clerk [1] are easy and very natural.

[0] https://www.flow-storm.org/ [1] https://clerk.vision/