My impression is that all of the current smart bikes are still very much a Gen 1 type product. They seem to mostly work but all have some issues with functionality/reliability/compromised design, that really would only be solved by applying lessons learned from gen 1 to future generations. No first hand experience of my own though.
I’d imagine with the Nordic track example, spares availability is benefitted by them having a lot more units of each model sold and out in the world, sharing of parts between different models, and just them being well established long running companies with the benefits of that.