Much simply indicates that it is not a little bit easier, but a lot. That doesn't mean it has to be the easiest.
1 billion dollars is much more than I have, but is is not the most money anyone can have.
A mouse is larger than an ant, a rat is a bit larger than a mouse, but an elephant is much larger than a rat. Yet, an elephant is not the largest animal that exists.
So something can be easier than something else; it can be only a bit easier, meaning it is almost as difficult, or it can be much easier, meaning that the difference in easiness is quite large. Still it may not be the easiest!
You asked about much easy
in your comments: that is not
We use very with standard adjectives:
He is very fast.
The book is very boring.
We use much with comparatives:
The other guy is much faster.
The the telephone guide is much more boring than that book.
With the superlative we normally don't use any amplification (superlative means it is the maximum already!) but in some cases, people do use very with superlatives:
Send me the very best developer you have!