If your distro ships the latest version of Chatty alongside mmsd-tng[0], SMS as well as MMS (both bidirectional) work supremely well, I trialed it as a daily driver for all of last month and didn't drop a single SMS/MMS. MMS attachments (images, didn't try video), group chats, everything was fine.
I still had to configure APN settings manually, but there was no faffing about on the command line, it just worked. All the other points, though, yeah... those are still accurate.
[0] https://gitlab.com/kop316/mmsd
Edit for clarity: this comment (and the link in the parent) references the PinePhone, not the Librem 5, though they're roughly comparable devices
Chatty used to use a libpurple plugin, but the dev realized the issues that came with it (as the old comment outlined), and it was moved into Chatty proper, which also allowed for a much cleaner SMS/MMS implementation too.
> MMS attachments (images, didn't try video), group chats, everything was fine.
MMS on Chatty actually supports arbietrary attachments, so you could send a binary file, a PDF, Video, whatever. Android and iOS will not understand them, but you can send it to another Librem 5 or Pinephone. One neat thing I tried was to use GPG over MMS. It was successful, though very manually intensive. There was thought into making GPG over MMS transparent in Chatty: https://source.puri.sm/Librem5/chatty/-/issues/671