> I'm not aware of instances where a delete is "far more work" than an equivalent insert though. That's not the general case, and I'm having a hard time thinking of any situations where that would be true.

Transactionally across related items with constraints it can explode fast.

If you've ever used FoundationDB this rapidly becomes the defining PITA due to the transaction size limits. Adding/inserting/updates are all far more predictably bounded.

But in that case, you need to compare like-for-like with the situation where you need to insert all the prerequisite rows too. You can't just compare a delete cascade with a single insert where all the foreign keys are already satisfied.