A lot of these services have a network effect. Being the only user on the platform doesn't create any value. You need to have someone on the other side to interact with. I was able to get my entire family using Briar as an SMS replacement. I'm working on a few ideas for networking people who want to use Briar with each other so we can have private forums for an array of interests.
Another idea I thought of was copying static websites (won't work for websites that are a service) and then putting them out there as a .onion website using OnionShare. I think it would be a good idea to create sites that are lists of .onion sites or add them to Ahmia (http://juhanurmihxlp77nkq76byazcldy2hlmovfu2epvl5ankdibsot4csyd.onion/) for people to find.
We might not be able to build a web that looks like the web of today but we can build one that's on par or better than what existed in the 1990's. In a lot of ways, that could be a very good thing.
I think the key is getting a core group of users in your friend/family community using it. I got all my family using Briar and now some of their friends are on it too, just because they knew people using it. IMO, Briar is the best message platform out there and I'd love to see more people using it.