Are We Stuck with Lean?

The author questions whether the mathematical community is irreversibly committed to Lean as its primary proof assistant, arguing that while Lean has gained dominance through influential advocates and its comprehensive Mathlib library, alternative systems like Metamath warrant serious consideration—particularly due to Metamath's superior soundness guarantees and set-theoretic foundation, as well as the emerging possibility of AI-generated formal mathematics libraries making alternatives more feasible than previously thought.