I recommend not ever making crafts. they just build up, and cause fps drop, while making trade too easy. don't make anything out of stone. only wood and metal chairs (also good aesthetically, while increasing difficulty, esp if in a desert). don't block off the caverns at all, when you discover them. makes the game much more !!fun!!. most of all, I recommend starting to play with less of a utilitarian viewpoint, and more of a narrative based one. The goal is not to win anything, or completely stop the goblins, its to make a cool more or less long lasting fort.
If you are looking for a technical challenge, play a surface game with no city wall (and a mine solely for mining), and attempt to mod out migration waves (beyond the first two hard-coded ones) by making something of negative wealth or something. or maybe try a multi city challenge, burrowing dwarves in their separate cities.
Most of all.... CAVERNS ARE !!FUN!!. try playing a game where you immediately dig down to the caverns, and have to survive building from the wood there, and a few stones and ore you shallowly mine. Getting a working military is a must then, and a challenge.
And when bored, play around with loyalty cascades.
I don't see where the dissatisfaction comes from, friend.
Though sieges ARE a little bit too easy to foil, if you don't limit yourself. That'll come in later releases