Beyond trainers: a universe of diverse models-Which is which?

I understand that the lines that divide beginners, intermediate and expert RC pilots are very vague and subjective, as it has been discussed in these forums many times.
Proficiency depends on human skills, practice, experience, etc.
It also depends on how others evaluate those skills.

It is clear to me how unclear these categories can be.
What I cannot understand is what makes the difference among the universe of diverse RC models that one can buy or build and fly beyond that first trainer, once it has been mastered.

In many RCU posts you read things like: ”you are not ready for that model”, “it is a high performance ARF”, “more advanced planes stall easily”, “it is not as forgiving as a trainer”, “those servos are not precise and fast enough for that task”, etc.

To make things more confusing, beyond the always recommended first low wing RC model, like Sig 4 Star or Goldberg Tiger, the breed of models branches out to the many motorized RC specialties: sport, fun-fly, IMAC, F3A, classic pattern, pylon, extreme speed, combat, warbirds, scale, 1/2A, 3-D, 4-D, multi-engine, etc.

Could any experienced poster explain the main differences, limitations and required piloting skills among those many models to those of us who have not flown such models yet?

This information could help us making better decisions when selecting our next ARF’s or kits, instead of investing and ending up with a model that we may want but is beyond our actual capabilities.

Thanks in advance.