They don't have to deal with the legal aspects of licencing content, nor need to do marketing, nor sales, nor have specialised teams working for features in specific markets; They don't have to ingest content, match content with potential existing ones to pay royalties properly (if not you get legally fucked), they don't have to do any kind of recommendations, so on and so forth...
I think you have a very simplistic view of how businesses work since your comparison is not even wrong.
What exactly? They didn't lay off 1500 engineers, I would imagine the bulk of Spotify employees handle all sort of licensing deals, talent management, ad sales etc. Telegram is a chat application that does none of this.
I think you have a very simplistic view of how businesses work since your comparison is not even wrong.