I would mostly say that it's just slow and AES is a much more modern and faster (partly due to hardware acceleration built into modern chips) that is already built info Firefox to support TLS anyways. There are some known attacks against 3DES now, but nothing that completely breaks it yet. And, since this is just for local storage, primarily, it shouldn't be as vulnerable as using 3DES for TLS channel encryption.
Thanks, even tho the comment above signaled sarcasm, the explanation was helpful for me, as I really had no idea what 3DES means and why it could be problematic.
Meh...not immune, just resistant. There's unfortunately a big difference. LLM slop is coming in at the corners, typically on articles that are less well-patrolled.