You are using your backup generator a lot, you need to seek out the maintenance schedule for your model and ensure you are following it!
In my area, Generac [1] and Kohler [2] are what everyone uses for their homes. The maintenance schedules are much higher than every 2-3 years. Good luck :)
[1] https://www.generac.com/service-support/faqs/maintenance-kit...
[2] (Page 60) https://resources.kohler.com/power/kohler/residential/pdf/tp...
I'd be more concerned about things nesting in it than anything else.
* the oil typically needs changed every 100 hours of operation. That was fine, until an ice storm knocked out power for 11 days to my parents house.
* if you live in an earthquake zone, most likely after a major quake the gas lines will be down.
This seems suspect to me. The ones I've seen call for it once a year or every 24 hours of run time.
The Onan/Cummins LP generator in my RV requires an oil change every 150 hours or annually, whichever comes first with the first oil change after 50 hours.
However, engine oil these days is very high quality and should last longer than a year.
Instead, I have a whole house natural gas generator. No gas to go stale. It powers my entire house. And it costs similar to this.
Maintence: Every 2-3 years, it needs an "oil/filter" change.
I have never had one before this house, but wow it is nice. We seem to be on some flakey power lines, we have lost power ~8 times in the previous year, ranging in duration from 1 hour to 2 days.