Private chats are a hassle to initiate and not multi-device.
Most use normal chats.
With anonymous accounts, using anonymous +888 numbers, whose price has increased from $16 to $1000+ in a matter of a year, it is indeed a very convenient playground for all sorts of activities.
It was the default method of contacting the dealers on Russian darknet when everything was a just a message board (hell, it was available without TOR) and not a proper marketplace
Why would a criminal mastermind pay $1000 for an anonymous Telegram account when they could buy a burner phone with a prepaid SIM included for like $20 to register and throw it out? In my experience the people who buy those are more Durov superfan than Keyser Söze. And evidence of criminality on Telegram predates the Fragment numbers by a while - for instance in like 2014-2015 pretty much the only time Telegram was in the news was in connection to ISIS. They could also just use Signal which is provably private.
"Burner phones" are a TV trope of the 90s and 00s. In most countries you cannot get a phone number without registering your ID with the telecom provider.
I’m referring to tracfones or similar prepaid devices which you can buy in the US for very cheap. In other countries if you apply yourself just a little bit you can get the same result. Greece has SIM card registration yet you can buy pre registered ones off the street in Athens. Latvia, Lithuania, Netherlands, Estonia, UK, and other countries have no SIM card registration at all and roaming works good across the EU. And you only need the number once to sign up.
There are no vendors, Telegram issues those numbers. So it's basically a pass to create account w/o mobile number requirement, if you're ready to pay for it.
> To get an anonymous number, you need to go purchase one through the Fragment blockchain... Durov calls Fragment “an amazing success” that already generated over $50 million in sales in less than a month.