Penicillin / antibiotics comes to mind. As well as vaccines. “Oh you’re body is being taken over by millions of microscopic organisms? Take this pill and it will go away. Maybe take this shot too so it won’t happen in the first place.”

And of course computers + the internet were a pretty big boom too.

My experience with Matrix is that the federation itself is a deal breaker. I have a pretty beefy server and good connection which was getting ddosed by running Matrix and timing out on so many requests for avatars/profiles etc. Maybe I did something wrong, but the whole experience rendered me quite skeptical to the viability of it as a federated chat.

That said I’ve had nothing but good experiences using it with big servers set up by pros.