The nice thing about Zwift is that it's fine if you want to toodle about at whatever speed you can handle. If you want to do that and try to collect badges from all the different routes, that can be a fun motivator in and of itself (that's where I started). I still sort of like that video game aspect of going places and doing things. If you want to do workouts, it'll give you those and some changing scenery to look at while you suffer (so you're not just staring at graphs - I have a short attention span and just looking at graphs always killed my motivation). If you're more motivated by group workout classes, there are group workouts. If you want to be social, you can find people to interact with. If you don't want to be social, you can either ignore the chat or turn it off. If you want to race once you think you're ready, there's that too. If you want to do a little of all those things, there's that as well. If you want to just try it out, you can ride 25 km for free each month (actually, as long as you start your last ride before you've used up your 25 km, you can keep riding to the end of that ride no matter how long it is.

Sure, the graphics aren't top of the line, people may argue if there are better workouts elsewhere, some of the physics may not be 100% real world, there's definitely some cheating in the races, and the user interface could use some work, but it's once place you can go and get all the different things, which sort of makes it the 800 lb gorilla because it has the most other users doing those things to interact with (and it has the most money to try new things).