Out here you can pick your fights with e-bikes. Ones with no number plate will be limited to 25km/h these should be chased down and overtaken - they are there just to provide a target to aim for! If they have a number plate then they are derestricted no need to feel bad about these passing you.
On a serious note e-bikes are extremely popular in Switzerland. I bought one myself when I hurt my knees a couple of years ago. It was a better option than not cycling. Switzerland also has more than its fair share of hills, so getting passsd on hills by OAPs zooming up hills with maximum assistance is just one of those things. Good on them for getting out on their bikes.
On a serious note e-bikes are extremely popular in Switzerland. I bought one myself when I hurt my knees a couple of years ago. It was a better option than not cycling. Switzerland also has more than its fair share of hills, so getting passsd on hills by OAPs zooming up hills with maximum assistance is just one of those things. Good on them for getting out on their bikes.