The use of telegram wallet is not what is bad to do, but how we could safely secure our assets from whichever path taken to have our asset, if you are not going to leave your wallet vulnerable for an attack, then its a good idea to make use of the telegram wallet despite being an online wallet, but when you're using a non custodial wallet and still remain careless about your keys or how you handle it, others may take advantage on that to scam you.