I was perusing Youtube as I do, and saw a new video from PythonMc ... I just realise the MC stands for Minecraft.
Anyway, the title was a bit different, introducing a Minecraft alternative. After that vid Youtube went and recommended a couple more along the same lines and something about a chat feature.
So I assume Microsoft is tightening their fascist grip on Minecraft. All is fair and well with that. It is their game they can do what they want.
Minetest
Many of the block games we see on the app store if not all of them have one thing in common though. They are built using Minetest
An open source voxel game engine. Play one of our many games, mod a game to your liking, make your own game, or play on a multiplayer server.
Minetest is not a Minecraft ripoff game, it is a Minecraft based game engine.
Change the texturing and it is as they say a Voxel based game engine.
Obviously their target market are people who play Minecraft but want to do as they wish. The base engine is not on par with Minecraft in many ways but the it is allows developers the ability to start with a solid foundation and reimagine the voxel builder game experience.
For the most part though many who just want to play will end up starting with Mineclone 2 it aims for parity with Mincraft Java version, and although no target version is set most features seem to be on par with version 1.12+ .
Specs
I am really not too sure about specs, and have only run the base Minetest game at home on my shitty 6 year old no graphic card having accountantesque PC.
The core Minetest is only 18mb and can be run off a USB, it does not seem to include any mobs in the base test game but has all the engines default building and block features.
Mineclone 2 I only played with for 5 minutes at work and it is a download of 34mb only.
My work PC has a fancy card so it ran using OpenGL4 so it will be interesting to see how it breaks when I get home and try it on my only OpenGL2 having ass PC.
Many features like redstone and mobs are not on par yet but I think for a base grind and build experience it should satisfy most binge players.
Mineclone is just one of many base games you can find on Minetest's Content Database with even more mods available to change each of those games.
With Microsoft maybe think they are too big to fail it won't be unheard of for Minetest to get a lot more backing and take their development to the next level. Ideally just to spite Microsoft but I assume unless they can find a good monetization path not much will happen.
They could always go the Blender Foundation Path and truly build a premier game using their own engine to compete. Godot is also working on that approach.
Developer Notes
Their Minecraft parity lacking features aside, Minetest is a great engine with a lot of default interactions with a vast world to populate as you wish.
The core language seems to be Lua which after a little scan of the docs is very interoperable with almost any other. Heck PHP even has a Lua extension.
I am sure it will just take a couple of these rockstar developers to drastically change Minetests ecosystem and that can only be a good thing for everyone.
Not to mention the play2earn possibilities with a open world codebase like that.
Images are from either Minetest or Minetest ContentDB

I stole @darthsauron's Kitty banner, so send the kitties some food on @give-cat-food so I can warrant the copyright lawsuit.
2% of this post goes to them and 2% goes to @dreemport because I am poor.