Unfortunately Lean’s distribution went from somewhat about 15 MiB in times of Lean 3 to more than 2,5 GiB when unpacked nowadays for no good reason. This is too much. Even v4.0.0-m1 was a 90 MB archive. Looks like that Lean’s authors do not care about this anymore.

Lean 3 was the least bloated theorem prover among Lean, Coq and Agda, and Lean 4 is the most bloated among this Big Three. This is very sad.

Personally, I stopped using Lean after the last update broke unification in a strange way again.