Honestly, Tom wondering about what makes Loki so extremely beloved among fans is the humblest thing ever, because even if he knew (sike, I think he knows very well),he wouldn't ever think to say it's him...
He wouldn't ever admit that his irresistible charm and absolutely phenomenal acting are what made us all develop this huge crush on Loki. Plus, the fact that despite Loki being written by literally a ton of people and draged through ridiculous storylines, he still manages to keep him somewhat the same - it still feels like Loki.
Tom understands and loves Loki so much - and it reflects in how he plays him. I'm not saying other actors aren't brilliant, but it just somehow feels so different with Tom?
I'm convinced that if it wasn't for him, Loki would just end up like any other MCU villain, no matter how good they were (imo, Kaecilius and Whiplash don't get enough credit...). But Tom got into that pretty small role so much and delivered such a performance, he just left everyone lovestruck.
Thank you for coming to my ted talk and have a very nice day.