Ok, so here's an issue with #nostr DMs.

Sometimes I wonder if someone has received my DM message or not, at least at the moment, and i think devs/clients are already working on something to get it working properly.

However, the idea of traditional apps where it tells you if the recipient has received the message, and if they have read it, is good UX but a lot of people (including myself) don't want people to know if I've read their message or not.

In which case, why not have it on a per-user, or even per-message basis?

By default its off, and then you can toggle it on for all accounts, toggle it per account basis, or highlighting a message and clicking "mark as read" so that the recipient knows I've read it. A manual / more hyper-control option.