whilst that is often true, I can give you many many examples of eBike shops who haven't been able to help customers with basic things like - brakes, suspension, wheel truing etc etc. And many of these things are more likely to need servicing than the e, bit of the bike.
So don't "just" buy from an eBike shop, find a good shop and spend you're money with them. They might be specialist in electric bikes, or they might be a shop that also sells eBikes, the level of service and experience is not to be prejudged by anything as simple as them claiming to be an eBike shop.
Because I am unwilling to spend this sort of money on an internet purchase, I did just that..
I went to a reputable local bike shop that also sold and still sells E-Bikes. They let me try one (impressive) They sell a lot of mid to high end cycles, they are really good with repairs and stuff, I can ring and book a slot for "while you wait servicing" they know their stuff and nothing is ever too much trouble..
My issue with the Bosch popping noise became a problem only because the shops best efforts failed to get any sort of help or support from either the bike manufacturer or Bosch with each advising to consult the other and then denying that the fault existed!. Any other bike related problem they deal with efficiently, but without some sort of support network and expertise/training on the electronics side, the best will in the world is not enough.
I advised them of the drive slip thing about 2 weeks ago and they are in the process of contacting Bosch to see how to proceed with it, which I am sure they will, whereas outlets such as yours and Martins would just deal with this as a matter of course. as per the OP
I do take your point though that an e-bike specialist is not necessarally an expert in the mechanical workings of a bicycle, and one shouldn't generalise by saying they are all the same, but I also think it is unlikely that your local bike shop that sells e-bikes will have a technician that has been trained to deal with the electronic side..
I did ask this question before I bought it and was assured (as they had been) that there were no serviceable parts in the Bosch unit and it didn't need any servicing at all throughout its long and trouble free life.