Rand is the strongest character in all of fiction, in my not so humble opinion.
Perrin's growth is too slow early on, and it's too fast in the Sanderson novels. There's an in world reason for Perrin being a slow learner, but from a storytelling perspective this turns into a problemover time. Not by book 5 though. His arc, while slow, is still acceptably paced in books 1 through 4. (And he isn't in book 5. He's rebuilding the Two Rivers at that time, and Jordan deliberately left that out.)
Mat from books 1 and 2 is the problem child of the group. He's immature and silly, and he gets into trouble only to need saving afterwards. I completely agree that Mat from the first two books is dubious at best. But... Jordan was aware of this, and Mat from book 3 onwards turns into a very strong character all of a sudden. In book 3 we get a glimpse of how competent Mat can be (in the scene where he defeats Gawyn and Galad with the quarterstaff, and him holding his own in conversation with Lanfear), and from there he starts to grow. He still makes stupid mistakes, and still needs saving every now and then, but we get to know him properly, and we see him change from a good-for-nothing joker into a great and loyal friend, and then onwards to a battle-hardened leader, while never really losing track of where he came from. There's a reason why Mat is a fan-favourite character.
As to OP's remarks:
Yes, the heroes are reluctant. They're mistrusting. They're dumb at times. Why? They're from a backwater village in the middle of nowhere, and they have no idea what's going on in the world. Their reluctance to accept their fate makes perfect sense. Their mistrust is frustrating to Moiraine, and perhaps to some readers, but no one in that situation would trust a weird wizard, considering all the prejudices they grew up with. Trust an Aes Sedai? Why? They never show up in Emond's Field and history is full of Artur Hawkwing stories about how Aes Sedai are schemers and cannot be trusted at all. Besides, they can do a thing normal people cannot. And what you don't know or understand, you mistrust. That's how human psychology works. You could argue that Jordan keeps this up for too long, but let's face it: the moment Moiraine decides - as a last ditch effort - to swear allegiance to Rand, and the subsequent Cairhien docks moment, become all the more powerful because Jordan cemented this idea into our heads so firmly.
So yeah, badly written? No, definitely not. Perfect for everyone? Also no, definitely not. If you don't have patience for slow arcs and extensive, repetitive descriptions, don't read WoT. Treat yourself to something that's less of an investment to read. Something that's faster paced, with less meandering sections and less subplots to distract from the core of the story. I recommend Project Hail Mary by Andy Weir. Also, Dune Messiah > Dune.