I think the primary reason very few people play Minetest is because of marketing and piss poor default gameplay.
I agree. "Vanilla" Minetest needs monsters, villages, villagers, fortresses, more ores, more items, etc. in order to compete with "vanilla" Minecraft.
It's so very close to being a Minecraft killer...but there seems to be strong resistance to adding more to the base game.
Unfortunately, right now, every query about vanilla Minetest being a little "barren" results in replies like, "Install some mods." sigh