Almost all of it, yes.

The packet format is awful, full of complexity, backwards compatibility mess, and serious security problems.

The spec is pretty awful in that a lot of the complexity is due to keeping compatibility with things that are a terrible idea. And also in that the general concept of a long lived key turned out to be a bad one.

The library or lack thereof IMO cripped PGP/GPG back when it was relevant. It's nigh impossible to make tooling for it, or it was until Sequoia showed up, which was extremely late. Things like doing stats on keys, or doing anything but what the binary wants to do were terribly painful until Sequoia.

The Web of Trust was an interesting idea for a while, but failed to transition to the modern internet.

By the time you fix all the things what remains looks nothing like PGP, so it amounts to "all of it is bad".