How else can you let people know you've seen their message?
In my life, read receipts are always on and are essential.
I like letting people know that "hey I was busy and haven't seen your message" when I haven't opened their message. There's no "Oh, are you ignoring me?" or "Are you ghosting me?" Because you'll always see when I see it, so there's never a question and if I haven't opened it yet, then I'm busy. There's no "I'm sorry I opened this and forget to reply for three days" or there's no "Oh shoot sorry I was busy haha" because other people can text me again and be like "hello?"