To me it's more an issue of unclear theme than plot, now that I think about it.

Early Goblins had a very clear theme. It was all about racism and turning the "humans good goblins bad" on its head, and showing that (what would normally be) side characters also have complex feelings and desires and all that.
So the Goblins went on to become heroes (or at least protagonists) while Forgath and Minmax had to learn not all humans good and not all monsters bad - and there were substories about the GAP saving innocent monsters from a monster-hunter, Dies resisting a goblin tribe that does fit the stereotypical evil image, fleeing a racist paladin, monster-slayer Minmax falling in love with a monster, and Kin overcoming her human-caused traumas in record speed.

The theme was not particularly original, but it was very clear.
But I'm not so sure if that's still the theme. It seems to have been largely dropped from the Maze of Many onwards. Even the sub-title (wasn't it "Life through their eyes"?) has disappeared!

If I was forced to do an analysis of the themes of Goblins for the past few years... I don't know. Something about becoming who you want to be versus accepting who you are?
With Dies and Fox' opposing views on fate, Complains and Big Ears turning into demon/angel, the gargoyle missing his old body, bunny girl's weird speech about dying peacefully, Forgath becoming a horrifying eldritch abomination. There are a lot of identity crises going around.

But that's reaching. The comic seems thematically a lot less clear than it used to be.