Talking to avoid scam telegram groups, but you offered anyone to join your groups since you claimed it's legit group.
Yes, we should avoid all groups including you.
Some telegram groups have awesome content that can be useful for trading while other groups have specific coin to shill time to time. Joining or not depends on personal achievement of trader since the group gonna be managed by trader like us. Scam social media accounts can be bad for inexperienced traders who blindly follow trading advices which same as shilling useless small marketcap altcoins.
It is your prerogative to join these groups or not. You can always peek whatever they are doing and they may indeed give you good tips. But if they are start shilling a particular never-heard coin, better get out because they are not here to help would be traders, but you will be rekt by their choices. You can always give them the benefit of the doubt and see what they are offering in their channel. If it is free, check what's in it, but if it is paid, better think many times before you spend that money.