It may be time for signal to adopt channels too even if they can't guarantee too much privacy due to the nature of the medium itself. But channels/rooms/groups have always been popular and will likely continue to be. They need the feature just to get more people to use private messaging as they join the app. Signal also needs to stop depending on phone numbers for usernames.

"Likes" are possible if you create channel messages via bots. Well, it's a kind of enhanced like. It's called reaction, you can predefine one or several smiles / text entries and channel readers can vote for it under the post. Some bots have convenient option to schedule posts or create self-destroyed messages and lots of other functions.

Comments are also possible via external bots. The discussion isn't really inside telegram though.

But navigation in channel is pain. Especially if you want to jump into the beginning where was no pinned message and channel has long history.

And when you subscribe for many channels it becomes a nightmare to segregate channels and users. They need to improve that experience.

Well, if it would sync, it's not private. Unless the app allows you to sync the keys offline. Telegram doesn't sync either if you enable e2e encryption.

But I agree that Telegram apps are great. Both Android ones, and the desktop ones as well. Small, fast, reliable, great UX.

FTR and as a user of Telegram who has often recommended it:

Telegram also requires your phone number.

Did you mean underrated?

IMO, Signal is actually overrated way too much. I don't want to repeat things too many times. My other comments here have a lot to say on this.