These proxy components have many of the same problems as centralized servers. If the proxy component goes down, your client stops working. You can't just down

These proxy components have many of the same problems as centralized servers. If the proxy component goes down, your client stops working. You can't just download any random client and have it work forever. You have to trust that the developer won't shut it down. Paying the developer can give you this trust (see IRCCloud), but most people aren't willing to pay for something they can get for free elsewhere.