I hate to agree because I hate WordPress, but when building something for others especially in a volunteer community it's still the go-to solution.

Pros, a ton of docs, easy non-technical customization, long term support, many already experienced users, made for basically exactly what you're doing.

Cons, it's WordPress, and the actual wp-loop is a nightmare of bad choices.

In every experience I've had, non-technical people have had a terrible time doing customizations. Not a single time have I ever seen them successfully navigate customizing pages without someone else stepping in. I see this as the worst case scenario: non-technical people can't do it and technical people also can't because they only have subpar tools to do so. I disagree wholeheartedly with this assumption.

Same. Or maybe something using PHP just as a basic templating engine (like how people used to use it). Something that can be copy/pasted to a dime a dozen cPanel powered shared webhost at a moment's notice.