I get that some people are just not great at replying to messages. I have friends who are like this and I mostly just accept that as part of their personality and not directed at me (although it does irritate me!). But one of my best friends increasingly is 'forgetting' to reply to my messages and I can't help but feel like I'm not a priority because she regularly messages on groups that we are both a part of, which makes me question whether it actually is personal. If it'd happened once or twice, I'd probably just think it was a simple oversight but it's happened over and over again, and I think that you have time to message on group chats you surely have time to respond to other messages? It's not complicated stuff that I've sent her either, it's just general chitchat of the 'how are you' variety. I get that it's not the most urgent message either and I don't expect a reply straight away, but I do think that if you have time to have endless chitchat on groups then the issue is not how busy you are, but who you're choosing to prioritise.