The objection is always the same: too many errors, no time. Both are true and neither is a reason to keep the checks off.

Migrate one file at a time

Strictness does not have to be a single commit. Enable the flag, allow a per-file suppression, and remove the suppressions as files are touched for other reasons. A codebase gets strict over a quarter without anyone stopping to do a migration project.

The errors are real

When we did this the largest category was optional API fields treated as guaranteed. Every single one was a potential runtime crash that only had not happened yet because the field was usually present. That is not a type system being pedantic; that is a type system doing its job on data that comes from a network.

any deserves a linting rule that makes it deliberate. Not banned — it has legitimate uses — but never accidental.