And as noted nearly every time this 7-year-old comment by Torvalds is mentioned, this is of course technically correct due to the properties of git's Merkle tree, but completely impractical as far as the human implications.

Consider: You've just written 20 lines of code, and you're creating a commit. Can you validate that all 20 lines were created by you before you commit?

Now, consider that you're looking to create a tag for version 2.0, coming from 1.4, with a net 4,000 new lines of code. Can you quickly and confidently validate that all 4,000 lines of code are as expected?

Clearly, the frequent, small validations are much simpler than infrequently signing huge releases. When integrity matters and humans are involved, small batches win.