I heard about Road Grand Tours half a year ago but it does not seem to be that popular. It is in beta right now and free. I don't know why because it has many of the things that zwift offer. You can see the other people that are online, you can connect a smart trainer and there are diffent routes.
Right now there is 4 routes and one under construction. The 4 routes are Cap Formentor, Passo Dello Stelvi, Pienza and Mount Ventoux. The route under construction is a small circuit called Canary Wharf in London. Cap Formentor is the route in Mallorca out to the light house from Port de Pollença. I have riden the route in real life and the Road Grand Tours is very recognizable.
I hope to see more people on the roads in Road Grand Tours