Thank you for this wonderful post! I have been a Telegram user for almost 3 years now and even I had forgotten about a few of these features.
I am from India and the majority of people here use Whatsapp as well. This means that I too have hardly any contacts on Telegram but it doesn't matter to me since I use Telegram exclusively to chat with my girlfriend.
Being able to use it on multiple platforms is a huge plus for me. Usually she will send me pictures she has clicked on her phone and I can just login to my PC and view it on my huge monitor. If she has clicked anything on her dslr, she will usually transfer the pictures to her computer. I don't have to wait for her to transfer it to her phone since she can easily use the desktop app to send me the pictures! I can also delete pictures from my phones gallery and not worry about losing it permanently since they are backed up in the cloud.
While this may sound like shilling, I just want to say that is just my personal opinion and Telegram is the better platform for my needs. Hope they introduce video calls this year and I should be a happy camper!