Nonsense! The game is not weak at all!

Unfortunately, the game is actually weak. I played it for almost 200 hours, 190 of them after patch 2.2.1, because before that it was impossible to play.
In my experience, there are only two "guaranteed" ways to have a quick and good start: through machines or through a good mage, like Minasli. Well, there is also a third way, through storm arrows for the Orcs. Everything else is demonstrably worse. There seems to be variety, but it's somehow "weak."

If you believe the reviews, you can conclude that the most important things in the game are the Campaigns and the animation of the intro cinematic.

I completely agree with you on this; in general, you can't trust reviews. It's all individual. The game will either appeal to you or it won't.

I would play it with pleasure if they fixed the bugs and made it so that the online Random Map Generator generates maps of size 300x300.

Well, they are generated in an external editor. It just takes a long time. If you want, we can play them.