If we're discussing viability of Minecraft on lower-end hardware, jumping from the voxel sandbox genre into the RTS genre (especially as you point out higher hardware requirements) is quite a stretch.
Minetest is as much of an alternative to Minecraft as Linux is an alternative to Windows. It works for some people, it won't work for most. It's less polished, requires some assembly (choosing a modpack), etc. They're quite obviously different games (as I pointed out already). But you don't need a degree in computer science, it's just a game. You can click on "new world" and start exploring and building.
What most people comparing the two seem to forget about, is just how much of a shitshow Minecraft modding is - and you don't really want to run the game without mods like sodium+lithium or optifine, because of how horribly unoptimized it is. I definitely prefer the Minecraft experience overall, but the game would've been completely unplayable on M1 Macs without tremendous community effort, whereas Minetest runs smoothly on a 12yro laptop with zero tweaking.