No doubt there are pros who do it the way you described, but what percent of WP installations do you think are managed by people like that?
There are many developers more skilled than "average joe" but below the level you describe, and they have plenty of other options: https://headlesscms.org
The other day I saw a ms-excel to webpage builder shared on news.yc voted to the front-page, there's also a google-sheets to app builder that did YC last year... I wonder if there's a market for notepad / word / docs to webpages, too? This article makes it seem like there might be one.
I personally use https://1mb.site for simple pages, but it still isn't easy to use.
Themes, yes, that's valid, they can be constraining. So is buying the wrong type of automobile. Deal with it.
Wordpress is PHP (and html/css/js/etc)and SQL. WP does not inherently do staging, so you set up a dev environment. You sync content from prod to dev, make code tests on dev, then copy them to prod. It's not hard.
> works fine on simpler sites [...] but it is not production-ready yet
I've found there are various gradations of WordPress developer and the "pro" guys are a very competent and very pragmatic bunch.
- Most "pro" guys limit the number of plugins they use.
- They use ansible or similar for provisioning and deployment.
- They use sane theme frameworks like sage, timber or stem.
- They know how to do caching without using clunky caching plugins
- They try to adhere to 12-factor where possible
- They do their own devops
I mainly consider myself an iOS/Cocoa developer but I do my fair share of web development including WordPress. I even sell a pretty technical WordPress plugin (https://mediacloud.press). I don't recommend or choose WordPress because it's a great platform, but because it can be a solid pragmatic choice considering all things like time and budget and client experience.
But for the average joe, it sure provides plenty of ways to shoot yourself in the face. That said, what other options exist for them if Wix isn't enough?