I've been using Zwift for 2 years now with my Wahoo smart trainer - I think it is definitely worth the $$.
A competitor to Zwift is
Virtugo, currently in beta testing so it is free. It has a few routes and several training plans you can ride. Definitely not even close to Zwift in depth/breadth, but you get a very similar riding experience to Zwift. It won't be free forever.
If you are a racer, there is Sufferfest and TrainerRoad.
Biking to videos never worked for me, YMMV.