lol cope and be normal I guess? I understand insta isn’t great with privacy but it’s a group chat for your room mates. Make a burner account instead of forcing all of them to download some app they’ve never heard of for one group chat with people they are forced to be acquaintances with.
They’re likely all thinking you’re the odd man out because you’re making a fuss over a group chat.
Normal people don’t care that much about privacy for a group chat between their room mates. They’re not and they shouldn’t have to go out of their way to fulfill your request for a privacy based platform for a single group chat.