If you can speak german try DSA.
Given your criteria, I highly recommend Artesia Adventures in the Known World. You can learn about the game here.
Given what you are looking for, Artesia might be a good choice.
True "fantasy heartbreakers" get their name from the fact that they are, generally, their creator's passionate ideal version of a classic, D&D-style fantasy game, doomed (hence the heartbreak) to failure because the market is flooded with dozens of games which are likewise their creator's "D&D done right".
Because it's sad to see someone put so much time and effort (and probably expose themselves to considerable financial risk) into something that inevitably tries to challenge D&D on it's home ground with the same weapons, and so turns into an also-ran.
There are classes and spells that are very like the D&D ones, there's usually an arcane/divine divide, and replications of many of the D&D features and limitations. You'll get a few differences; it's really unusual for a modern game to have armor that makes your harder to hit instead of allowing you to shrug off more damage, for example.
I also think that, in many ways, D&D's position as the market's behemoth makes it easier for gamers to accept changes to it.
As was mentioned in the the OP, Rolemaster is generally given as the example of a game that has too much crunch. Each weapon had it's own damage/crit chart which took up an entire page, as did each crit chart, as well as the several critical fumble charts. I can't remember how spells worked, but I'm sure they also involved large charts. This is before you get to charts about "how likely is inn food to poison you", and other such details. It also had lots of situational modifiers.
GURPS certainly has the capacity to be crunchier, even if most people seem to only use the simple version(s) of the rules. HERO is crunchier.
For smaller games, only the people who like it are really engaged by it. You don't see consistent criticisms. I think that's actually a significant drawback for them. It's nice to have fans who love your game, but the people who seethe and rant can be pretty useful when it comes time to figure out what you need to fix. If all you hear is praise, you're stuck with guessing.
Two words: grognard capture.
Not all change is the same. Grognard capture causes RPGs to grow and expand, but it also causes to core gameplay to remain unchanged. So the "core" rulebook might have very different contents with each iteration, but most of the change is the incorporation of earlier expansions into the core. The "nucleus" of the core remains unchanged.Something here isn't computing.
Firesnakearies said other RPGs change very little. Mike says that grognard capture explains this.
But grognard capture causes RPGs to change a lot. That's the whole point of grognard capture. The grognards take over and move the game beyond its core, doubling the size of the rulebook, making it increasingly complex, and likely (but not always) making the game less accessible to newbies.
I think I can tell that what was actually meant was: a) other RPGs have grognard capture, which causes the RPG to preserve vestiges of their earlier editions, and b) D&D has been brave enough to discard un-fun vestiges and "refine" itself.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.