JWT is secure.

I just noticed that after JWT was created, people would just slap on JWT like an end-all because JWT sounded secure and they thought it was all that they needed to do.

That’s my only “problem” with JWT but to be honest, people will build insecure systems anyway.

Exactly, it's like saying that Postgres is insecure because it allows SQL injection attacks when untrusted user input is injected into the query directly.