I use Telegrams. For me, this is the most convenient social network in all respects, because it is very safe. And I know here a lot of competent investors in cryptocurrency who share their experience of investing. This has a positive effect on the spread of bitcoin, I think.
In my opinion social media is a very powerful tool for promoting crypto, because it is used by users all over the world.
In many successful promotions on social media, because the similarity of ideas, hobbies or communities makes it the best marketing place.
Telegram is as safe as you make of it. But if you're someone who falls for scams and tricks, then it doesn't matter what grade encryption Telegram has, just like it doesn't matter about Bitcoin's cryptographic superiority if you don't practice good security habits.
Anyone who thinks Telegram has a positive effect on the spread of bitcoin should do a poll of Telegram users. I bet you, not even 10% have ever spent anything with Bitcoin.