I have ADHD myself, so I understand how it is to struggle to concentrate, but I also respond to a message as soon as I read it, I find it super disrespectful for someone to not at least acknowledge that they have read the comment, even if it is a simple "hey I read it but I can't reply right now"

In my eye communication is a two-way street and it's a form of respect between both parties and if one end of the party isn't going to respect the conversation enough to at least acknowledge it, then you start questioning if it's worth engaging in the conversation in the first place.

Personally I would rather be told hey sorry I didn't get your message till now, rather then learn that they had read the post, didn't say anything and then forgot to reply later. It's a slap to the face.

addition: It's just a minor pet peeve of mine, it is also the reason why I try to avoid any platform that has read receipt notices, because in my opinion it just information that the sender really shouldn't know in the first place because it opens them up to knowing it was read they just didn't bother responding