hub motors put all there Torque through the spokes and rim and will come loose esp with off road use it simply puts the strain on another part of the bike and they will snap esp off road use.
hub motors also can and have snapped the rear triangle with the Torque they can pump out and massive ones need custom steal frames like the stealth bomber type frames.
hub motors also dont work well on fs bikes and using one off road going down a black trail will only end one way with broken or loose spokes.
most hub motors use the qr system where my bike has 12mm axles front and rear because if you ride down black trails you need them to keep the wheels on!
race to win or crash trying
I would bet you are the owner of a mid motor e-bike, and you have probably never ever owned a hub motor bike.
Also I completely disagree with your assessment as well, with your "imagined" failures. Properly made frames do not snap as you describe under normal heavy usage.
Where I live and ride, a Brit would probably call it mountainous, we might say "hilly", but I have never ever had an axle snap, except on an old mountain bike I had about 20 years ago, after it was pushed over, falling on concrete (not up on the hills!), because a car driver simply could not drive. It cost me less than 5 UK Pounds to repair!
I also know quite a few e-bikers, and we chat from time to time, and the only ones seemingly getting bad and expensive problems are all mid motor units between 2 and 4 years of age. Most with less than what I would term "medium usage".
And the costs of some repairs (mostly Bosch!), some have had to have made, would have paid for BOTH of my rear hub bikes when I bought them, first one was secondhand the second one brand new!!!
On both my rear hub motored e-bikes, I have never had a spoke snap, or bend, or need replacement, or a frame break, in probably 30,000 Kms plus of riding in over 10 years. Rarely has a spoke even needed to be adjusted.....though I check them around once a month, just as I did with all the normal bikes, I previously owned....
Remember, a rear hub motor is direct drive to the rear wheel, the chain does not get "strained" in any way, and only the muscle power of the rider goes through the chain, and I need to change my chains at about 3-4 years, the latest bike still not, probably because I tend to use more motor as I get older.....
And as I mentioned before, nothing has gone wrong with either motor either, so I have yet to look inside one for any reason!
My running costs are usually around a new set of tyres per year, and two sets of brake pads a year.
A brake caliper that broke due to UV light on the plastic (cheapo) adjuster, I did replace, but I repaired it using Epoxy and stainless steel bolt, and washers, and put it back on the bike about 10 days later......
This first picture shows the way the adjuster was bleached and made porous by Sunlight (only on the front, as the rear brake is covered by the panniers, and even 4 years later, still looks like new!)
The next is the epoxy and stainless parts used to replace the plastic adjuster, and is still OK
(note to the epoxy "unbelievers" here!).
Here is the part that I repaired from the "inside", all held very strongly with correctly applied Epoxy:-
The outer part is the actual metal part of the original adjuster, that no metric nut fitted, sadly! So I simply removed the plastic part, and glued stainless steel parts in place, that I can adjust using an Allen key......Also filing the surface absolutely flat, to contact and adjust the brake pad correctly of course.
My cycling, over a great many years (more than I really care to remember), has cost me only very tiny amounts of money to support completely, as I can just about repair anything, but on my bikes, repairs are few and far between......
And at 75, in a 9 days time, I do not anticipate that to change much!!!
But, if you have truly experienced such failures & Breakages as you declared, please be so kind as to add the name and model of the e-bikes in question here, so that all our members are duly forewarned. Its the friendly thing to do.
regards
Andy