Well, TON definitely has room to grow since it is a blockchain that developers can easily built upon, and Telegram is extremely popular, especially with the cryptocurrency crowd. However due to so many scam accusations and combined with the anonymous nature of Telegram, it does not seem like a very trustworthy app when it comes to trust and money. Also, the app developing is quite limited. Meaning there is only so much you can build on top of TON. If Telegram itself were to become unpopular (because something better came out) then the entire TON blockchain would become irrelevant as well as all the apps on it.

I just see too many weak spots to be comfortable with investing in TON.