The reward mechanic in Minecraft (modded) is that you work very hard to get to some point, then you get there and unlock a number of new things and gameplay. That’s typical of the fun of tech trees, you expand your possibilities, see more things, get more toys to figure out and experiment with. With a large modpack you have so many different toys and a whole lot of freedom.
The other half of the exquisite reward feeling is that it’s not just unlocking new toys, but also access to certain tiers that immediately make everything you’ve done up to that point much easier. So it keeps changing. You get to work hard, but then you look back and have means to compress that path. So the hard work is compensated by something that escalates the scope.
But it depends what you want. For me the early game is the most fun across the whole genre. I enjoy learning how stuff works, especially if it’s well directed.
It depends a lot on the modpack, but Minecraft is not Factorio, so you have many different types of gameplay that make the experience less focused but richer. I don’t even know how it’s possible to get bored since it’s almost overwhelming all that it throws at you.
Even stuff I always considered shallow, like creating a nice place well decorated, it acquires a whole new dimension in Minecraft modded. Because if you have to spend a long time in this type of game then it makes sense to make it nicer. If decorating a house is the whole end goal, then I’m bored before even starting. But if it’s just incidental and working alongside other activities, then it acquires its purpose and contributes to the richer experience. I keep getting distracted by countless of sidetracks, and time flies.
Suggestion: before giving up try the Lost Era pack I linked above. After an introduction it opens up a number of alternate paths, giving you quests for everything. You get to experience the variety more directly (and it keeps the standard recipes, working with the classic version of GregTech).
P.S.
I played Omnifactory for a few hours to try it, but of course I picked the “self-torture” edition because it doesn’t give you the diamond hammers at the start, and I picked the standard overworld. I actually enjoy to start from nothing and work hard to get some crap tools. I enjoy to have that kind of long progression and rags to riches path. In fact I think that being able to get iron just a few minutes into the game is kind of shallow. I think GTNH has a much more complex and longer early game (I don’t think there’s any way to get iron, and you have to work with copper for a while).
In GT6 it’s very well designed (even better with Punch Me Not). If you punch a tree, you get hurt. Same if you punch the ground. So what you do is starting to walk around to explore a bit, and in the meantime you collect sticks and stones that you find everywhere. Different types of stone indicate the type of metals you’d find if you dig, so you don’t need any advanced scanner like Omnifactory. Then you get some gravel, take flint, and you can make some basic flint tools. It’s all layered meaningfully and makes the experience fun. It’s going fast that actually kills the feeling.
