Excel dropping leading zeros (as in ZIP codes) was a crazy design decision that has certainly cost many lifetimes of person-hours.

And forcing 16+ digits to be floats, destroying information.

Yeah have had similar struggles with social security numbers.

For example:

Scientists rename genes because Microsoft Excel reads them as dates (2020)

https://www.reddit.com/r/programming/comments/i57czq/scienti...

I was so glad of that story. It gave me something to point to to get my boss off my back.

But it handles it better than Json.

Depends on what you mean by "better". I would rather software not handle a piece of data at all, than handle it erroneously and changing the data without me realising and thus causing all sorts of issues after.

In practice, web browsers accept the tag soup that is sometimes called html and strict xml-based formats failed.

The browser are not a database (unlike excel). Modifying data before showing it is reversible, modifying it before storing it is not.