Yes [1].
Nobody expects the average person to install 'non-trivial systems like emails', just like nobody expects them to configure, build and install Android or iOS on their mobile devices yet still they use those devices without undue problems. They even update the things to new releases, mostly without problems. The reason for that is that someone went to the effort of packing up Android and iOS so that it is possible for just about anyone to install them on their devices.
> We get paid to do things we want to do and are good at, and we pay others for services/goods that we need but aren't capable (or don't have the time or interest) of doing it ourselves. It is unreasonable and impractical to expect everyone to do everything themselves.
This is where free software enters the equation, a few people working on a project like this can make a huge difference. Maybe those people get paid to work on free software, maybe not, this is irrelevant in this context. What is relevant is that digital technology does away with scarcity, the work of a few or one can be made accessible to the world without cost other than that of internet access (for which, as stated, the user already pays).
[1] While I do not have a car myself I do fix my wife's as well as my motorbikes and tractors. I generally do not make my clothes but I do fix them. Yes, I fix my own plumbing, not that strange given that I restored and partly built our house which includes installing said plumbing. I'm currently building roof trusses for yet another build-out. Specialisation is for insects.