The biggest red flag is when they try and stop you from pasting your password (or anything else for that matter) breaking password managers.
There are years-long arguments on social media with companies who do this with actual security experts telling them they’re hurting security (including referencing organisations like the UK’s National Cyber Security Centre) and their only response is “we don’t allow pasting for security reasons” but they can never explain how it helps security - because it doesn’t. It drives me mad.
That’s what’s great about all these companies. They take credit for, and try to derive value from, things they didn’t actually create. Reddit keeps on talking about “their” data that was created by users, for free, and moderated by other users, also for free. Yet it’s somehow theirs and they can sell it?
Twitter didn’t invent hashtags. They were user created annd eventually incorporated in to the service.
These services add very little value, but they believe they add it all.