While Vim's regexp-based syntax highlights certainly has limitations even in fairly simple cases, and I would love to see something better, the downside of these things is that people get carried away and add colours to everything.
A little bit of colour is very helpful. Ten different colours seemingly chosen at random is not.
I tried that LunarVim thing, which was a somewhat frustrating experience as it doesn't work on light terminals at all (setting background=light and :colorscheme default seems completely broken), somewhat ironic that a project which bills "better colours" as one of its main points doesn't actually work with a common background colour, but okay.
The colours for Go are ... not great. Is there any point in highlighting string literals in a different colour than numbers, and bools yet another colour? What extra information does that convey? Or what's the point of highlighting operators in blue? Giving _ its own special colour? That doesn't make it easier to read – quite the opposite as there's an overload of information.
There are 10 unique colours with the default Go colorscheme (vs. 4). This alone is noisy and distracting, but they're not even especially well chosen as there's significant overlap with completely unrelated things highlighted in a different colour (escape sequences the same as functions, or nil the same as func; no idea what the point of that is as it's not even a keyword).
In short, these tools are nice, but I fear it will lead to an explosion of extremely badly designed colour schemes where people add stuff "because they can" and "ohhh, colours!" without actually thinking if it's a good idea or not. I saw this with vim-go where people constantly sent in patches for dubious colour scheme changes, and you spend forever argueing why it's not a good idea, and at least "it's very slow and will complicate things a lot" was a meaningful barrier.
Darn I sound like a grumpy old man... But really, these are design issues I don't see enough consideration of. No colours is bad; some colours is super helpful, but loads of random colours is even worse than no colours. There's some research on it too; NASA did research for colour usage in flight control systems for example and came to the same conclusion (which I can't seem to find right now). Another fun example is the "count the triangles" vs "count the red shapes" in [1]; counting the red shapes is easier, but counting the triangles is easier in the monochrome version vs. the coloured one.
[1]: https://homepages.cwi.nl/~steven/Talks/2019/11-21-dijkstra/