Known vs Unknown Senders

I’m on a text message group thread with old friends that I enjoy staying connected with but the problem is, they text A LOT. I’d rather not ask to be removed but am more so looking for a way to engage at my convenience rather than their messages jumping to the top of work related message, etc. I envision texting similar to email where I should have the ability to put them into folders which I can look at when time permits.

Several things I’ve tried:

• Muting the conversation. This removes the notification but when you open messages, they’re still rising to the top of the queue.
• Deleting their contact in my phone thinking this would filter their messages into “Unknown” senders but sure enough the next text I received had all of their names on it and went into my “Known” senders text messages. I guess since I’ve messaged them before, iPhone knows them even when their contacts aren’t in my phone
• Deleting the thread

I know I can block their numbers but that would make it so I couldn’t keep in touch any longer. Also, I can ask to be removed it again, rather not go that route.

With all of the communication that comes through text, you would think there would be a way to organize and separate out what’s important and time sensitive vs what is random and for leisure.

also, any apps that you can suggest that do this would be helpful. Or we can create one? Thank you in advance.