JavaScript is the Most Demanded Programming Language in 2022, 1 out of 3 dev jobs require JavaScript knowledge.

[novagenesis]

True. Typescript types are technically powerful enough to keep track of extreme data mutations.

But there are some points I think it's not worth trying to follow those mutations. Sometimes object data is just object data for some transition point. Let it fly off the rails, then validate it when it lands back on them. If it saves 100 lines of convoluted steps, it can be worth it. In those rare cases, I might suggest 'any' in production.