Diminishing confidence is not usual and I find, at age 73, it's creeping in.
So I too, am looking to simplify systems. The Genset, which I built and installed 20 years ago, seems now to require quite a bit of maintenance. I've just replaced the starter motor as a solenoid alone wasn't available. This was a p in the a due to very difficult access to that side of the engine. My own fault entirely. So....next time there's a problem, it's coming out! I have a propane stove, diesel heating , a 100amp (24V) alternator on the main, shore power charger and 200W of solar. I'll double the solar, which is adequate in summer as is, and eventually change to a LiFePo4 house bank.
The upside of this will be a lighter, more balanced boat that may just burn a little less fuel!