Since Minecraft 1.19.1 with the new chat moderation system, I have vowed to avoid playing Minecraft. So I finally gave Minetest a shot a few months ago. I knew it was considered a game engine, so my impression was I would have to find and download standalone games. But when I learned about the Minetest launcher, I realized it was all there in one download. And if you join a server, it installs the necessary mods automatically. So this is a lot more like Roblox or Curseforge. I think calling Minetest just a game engine is kind of underselling it and maybe it should be branded differently.
I also think it shouldn't be described as an alternative to Minecraft. Minecraft has been in development for 13 years, most of that time with hundreds of employees under Microsoft. With virtually no height limit, Minetest beats Minecraft technically in a lot of ways. But I still think Minecraft is a much more polished experience overall, and it can take a bit to get used to some of the differences.
Instead, I think Minetest should be described as an alternative to modded Minecraft, because this is where it really shines. After all these years, Mojang has not added any modding support to Minecraft. So Minecraft mods can be clunky, buggy, and every Minecraft update breaks all the mods. Minetest, on the other hand, is built only for mods, so mods work really well.
When you play a modpack, you are not playing for the vanilla features of the game. Some Minecraft mods even remove vanilla features for a brand new experience. So why put all that effort making a free to play mod for a pay to play game, when you can do it for a free to play game?
If you are a mod creator, you will have an easier time modding on Minetest, anyone can play your mod for free instead of paying Microsoft $30, and players will have the same, nay, a better experience, because modded Minecraft can be incredibly buggy and prone to crashes. So Minetest beats modded Minecraft hands down and if I had known sooner I would have played it sooner.
I'm really enjoying Minetest; it has a lot of potential.