I bought a lightly used Wattbike Atom just after the pandemic. I have used it, on average, 8 hours per week since then and it is still going strong.
In part this is down to the robustness of the unit. But also, that it has been serviced well.
I have used the Wattbike General Home Service twice. I don't know how dependent the quality of that is down to the engineer who attends, but I can tell you that the chap who did both of mine did a superb job.
Having watched what he did and asked a few questions, I now do my own basic service regularly - cleaning the drive train.
The drivetrain becomes noisy over time and it needs a clean every 50 hours or so of use. Basically, remove the chain, give it and the bits it touches a good clean, put it back on, lube it and the bike is back to near silent again.
Removing and refitting the right hand side of the cover to get at the chain is the biggest part of the job. Whether you put it back on (or not) is worth considering.
One thing I will say about the Atom is that it is a very solid thing. That makes it, IME, uncomfortable due to there being no movement / give in it at all. I fixed that with a rocker plate - transformational to the whole experience and I would not be without it.