Fun fact: Postgres is one of the few databases to do this right. "varchar" is just an alias for the "text" data type, which has a limit of 2GB (last I checked). A small amount of text is stored inside the row, and the overflow is compressed and stored in a series of linked child rows. The system is called TOAST, and quite fast. So the underlying storage is completely abstracted, and setting a limit doesn't impact storage; it only enforces a limit on what input is allowed. MySQL's text type, on the other hand, is like a binary blob and has (last I checked) different semantics than the varchar type.

I mean, there’s good reasons to limit the size of fields in database tuples - relational databases are made for storing small to medium amounts of normalized data, you can abuse them (and I have, storing a couple million 60-200K PDF’s in a Postgres database at work) but you can shoot yourself in the foot by creating tons of 60% full pages and the stupid amount of extra IOPS those wide columns create.

Still, not allowing unrestricted text and binary columns is still silly, so I agree for the most part - but you still need to know what you’re getting yourself into when you start making wide tables.