I'm with you that they should keep charging the same higher prices for ebikes, just saying the price differenciation is already there.
Unsurprisingly it seems the markets are heavily split by region/country. I assume your comment is about the US market, and I'm kinda glad cheapish bikes are getting the spotlight and more love overall, as it's a neat gateway into biking.
In regions where biking has been a commodity for much longer (like Vietnam/Japan/Korea etc. in the SEA area), if the whole drive train is not electrified the front hub will be used for powered lighting and they won't bother with a disk brake. Which makes sense as they're not expecting people to go anything fast, efficiency is already down with the dynamo hub, and those will easily weight 20+ kh anyway, and they wont to get the price down wherever they can. Same way forks are super cheap, brakes themselves are lower grade (rear brake will often be a ribbon brake) etc.
On the other hand those country also have a huge chunk of electrified bicycles that will have complex drivetrain, high quality parts and of course disk brakes and they'll be services by bigger shops and certified people, and not your random small one-man shop at the corner of the residential street.
Most ebikes still use standard derailleurs (usually a 1x drivetrain).
For internally geared hubs, Nexus or Alfine IGH are the most common, and apart from getting the cable tension right, don't need any specialist equipment (though the Alfine 11 speed hub is apparently somewhat tricky because it has to be packed with grease).
Most IGH still use chains, belts are less common. Newer chains are rated for ebike use but that generally just means they're more robust.
Belt drives do need to be tensioned properly but again, this doesn't requires specialist tools nor does it require a huge amount of specialist knowledge for a bike mechanic that is (there's literally an app for that). Enviolo, Roloff and other gearbox style systems are specialist equipment and not what you would normally expect a regular bike shop to do intricate servicing on.
Also, internally geared hubs have been around for almost a century and both IGH and belt drives are used on regular bikes. You would expect bike mechanics to be able to deal with them easily.
So by and large, they really are bikes with motors. Yes, there are some things that are more complex but the majority of things are basically the same
My LBS, which is familiar with Gates belt drives, uses for tensioning a rather old-looking metal contraption provided by Gates. Definitely a specialist tool. The phone app for tensioning a belt from the frequency of the twang it makes, is only for end-consumers. Shops are supposed to use the dedicated tool.
You mean, a mountain bike only with an electric motor? Because that's what you just described, minus a battery and motor. Hydraulic brakes have been on bikes for years, there's no more "specialist equipment" required than saying that a third-hand tool for caliper brakes is "specialist equipment". IOW, hydraulic brakes are bicycle brakes in a lot of cases these days. Internal gears? I'm approaching retirement, and multi-speed, planetary gear hubs are what I rode when I was a kid; nothing special there. As for the chains and sprockets, well, your local bunch of amateur racers will put out more wattage than the measly 250W + rider output that an electric will put out, and they use the same chains and sprockets that you do. (I'm not counting electric motorcycles with a "bike" label that put out 1000W.)
So, yes, they are "just bikes" with an electric motor. The exception might arguably be the mid-frame motor ones that require the frame to be designed with the idea of mounting the motor, but even that's just an implementation detail: the rest of the bike is the same.
Another issue comes with the actual battery and motor, because if you don't get a bike with a system from Bosch, Shimano, or Yamaha, chances are you're on your own for support. Bafang etc are much cheaper but the onus of support is on the vendor directly -- a bike shop can work with Bosch to find and fix problems, but for the Bafang gear they have to deal with whatever (possibly fly-by-night) vendor resold the gear, because Bafang won't help much.