Let's take a moment to talk about our 1.7.10 lord and saviour, GregTech New Horizons

More seriously, depends on where your cutoff of "kids" is, but fuck gatekeeping things because they're "for kids" - Minecraft is fine for kids, and it's fine for adults. If you want to hop on your procedurally generated world and explore landscapes, or build houses while working for every block and managing the logistics, or build convoluted redstone contraptions in creative, that's a great use of your entertainment time.

And on modded Minecraft, I haven't properly played GTNH, but I recommend The Lost Era if you want a nice 1.7.10 modpack with balanced progression that doesn't try to be extreme. When playing it, I realized how many mods are being updated, and how much of that work seems to be done specifically for GTNH, so that's extra appreciation I have for it.