What would you suggest for the start of the range you mention? I have been quite happy with my Edifier 1280's and they were just 120 bucks. They get plenty loud and detailed and visitors always appreciate them. I do have a DAC /Amp and few open backs / IEMs but never really bothered with speakers since you can really only get the one.
I'll defer to Wirecutter here as they have always done a good job in my experience! Note that some of those bookshelf speakers will require a separate amp.
However... if you're happy with your current speakers, perhaps there's no reason to upgrade! A lot of the choices I've linked to above will come with an increase in size and/or complexity. And I think those Edifiers are pretty well regarded in general.
While better than typical hifi rags, wirecutter and the like are still entirely subjectivist and rather off the mark more often than most. My point above was to lead by measurements of some sort, and places like Audio Science Review and Erin's Audio Corner provide just that.
EQ is absolutely important for the vast majority of systems. But use proper PEQ that has been derived from measurements and don't just wing it by ear. Just as important in most environments is using some sort of room correction (and preferably room treatments).
I agree with everything you said. Sometimes I do just send newcomers to Wirecutter if it seems like they're just looking for a recommendation (along with some lite foundational knowledge) rather than looking to really get their hands dirty with the hobby. It may or may not be the right call. But thanks to you they've got a couple of paths from which they can now choose.
I'd ignore any reviews that don't provide a host of measurements. Even well intentioned subjectivist sites get it wrong more often than right.
Go here, click on speakers, sort by price, and follow the preference score (generally around 5+ is an excellent speaker on the low end), then read specific reviews for more detail about their strengths/weaknesses:
There are a handful of brands, while not cheap, that provide excellent value as up/down their lines they are nearly infallible, such as Genelec, Revel, and Neumann. There are also some that are usually excellent such as Kef.
