You are so right. Many of those channels just tell you BUY NOW, SELL NOW, etc. Hate those signal groups that delete their negative trades, only show the positive trades and basically just scam people.
I suggest to use channels that give objective information (like the 100eyes one just tells you that there is a support zone, not if you have to enter a trade or not, and the whale one is objectively telling you what transfers are made) so that you can analyse it and combine all information to decide for yourself whether to trade or not. There is some use in getting information from Telegram, because with some 130+ coins and a market that never sleeps there is too much information to constantly process yourself.
Like those news, events, happenings and etc. And once you've managed to get experience, you will definitely understand or have that feeling of when is the right time to sell and buy and what coin to buy.