There are good and bad wikitext dialects
One of the things about wikitext dialects that I've essentially asserted in passing is that there are 'good' and 'bad' dialects. Perhaps this raises your eyebrows, either because you think all wikitext dialects are a bad idea or because you don't see what creates such a difference.
There are two possible criteria for goodness in wikitext (or in general any simple markup scheme), depending on why you're using a wikitext. For a markup aimed at empowering beginners, what probably matters is how simple, straightforward, and error-free it is. This ties into your desired style, in that it should be both easy and obvious to create the kind of content that you want, marked up and styled in the ways that you want.
For a markup aimed at smoothing the way of frequent authors, what matters is how unobtrusive and smooth the markup is. The more that you have to spray large amounts of special text all over your content (and the harder they are to tell apart), the more the markup is getting in your way and the less it's giving you compared to just using normal HTML. This leads me to feel that good wikitext here either looks close to what you'd write in plain text or is simple and terse. The goal in both cases is to minimize the extra friction of adding and using markup.
(I feel that aesthetics matter here because you don't just write your text, you also read it as you're writing and revising. A wikitext dialect that is obtrusive or ugly winds up obscuring your actual content with its markup. If you can't easily read your content for flow in its un-rendered form, well, that's a kind of friction.)
A bad wikitext dialect is one that moves away from these virtues. It's obtrusive and verbose; it's complicated and perhaps hard to keep straight; it makes it hard to decode what the markup means at a glance (due to eg using a bunch of very similar markup characters). It gets in your way. It may make it too easy to put markup mistakes in your text or too hard to find and fix them. Overall, it contorts and distorts your writing process.
(My fuzzy view is that a wikitext dialect being incomplete doesn't necessarily make it bad. In the abstract incompleteness just makes a wikitext unfit for some purposes, but then if you're forced to use the wikitext anyways for these purposes it can turn into something that's getting in your way and thus is bad. I wave my hands.)