by default telegram doesn't encrypt anything. I'm not sure if you where implying that telegram had encryption and therefore hiding illicite activities.

The problems is the huge telegram channels spreading hacks and illicite tricks.

There is no such threats against Signal which is way more privacy oriented. (except for some new laws in UK where Signal said if they are applied, they would withdraw from the UK market:https://fortune.com/2023/07/13/signal-president-mass-surveil...