Unfortunately I think that while there’s a decent number of power users and people who have the aptitude to become power users who will make use of software made to be deeply customizable, they are outstripped many times over by people who don’t see software that way and have no interest in learning about it. People are quick to point fingers about why the situation is as it is, but the truth is that it was always going to be this way once computers became widely adopted. It’s no different from how most people who drive cars can’t work on them and why few feel comfortable making modifications to their houses/apartments. There’s just a hard limit to the scope and depth of the average individual's attention, and more often than not technical specialization doesn’t make the cut. No amount of gentle ramping will work around this.
That doesn’t mean we shouldn’t build flexible software… by all means, please do, but I wouldn’t expect it to unseat the Microsofts and Googles of the world any time soon. I do however think that technically capable people should do anything they can to further the development of not just flexible, but local-first, hackable software. Anything that’s hard-tethered to a server should be out of the running entirely and something you can keep running on your machine regardless of the fate of its developer should take priority over more ephemeral options.