I have more than once subscribed just to report a bug or send a patch because the mailing list rejects emails from non-subscribers.
Edit: Btw, yes I have done the periodically-check-archive thing in the past, thank you. Hated it. Also missed a response once because I forgot to check and replier didn't CC. I realized like a month later.
It is unfortunate that there are poorly-managed projects with poorly-managed mailing lists (just like there are poorly-managed projects on Github), but sourcehut at least requires a properly-managed mailing list, and I think you should evaluate this workflow on that standard. Tell poorly-managed projects to move to sourcehut, if you want to fix this issue.
Even then, you’re free to opt into daily digests if you’re a subscriber.
The message ID allows you to reply to individual messages and threads nonetheless.
Edit: Btw, yes I have done the periodically-check-archive thing in the past, thank you. Hated it. Also missed a response once because I forgot to check and replier didn't CC. I realized like a month later.