Not a fan of the low vs high term. It’s more like a spectrum. Basically the ideal high tech is co2, high lighting, powerful filter. Low tech is well, the opposite. Low tech could mean a bowl of water with a beta.
but in reality most people just consider is there co2? Ok high tech. But really you could run a tank with co2 that is more akin to low tech with a cheap light, and a weak filter. It’s just whatever works best for you and your aquarium.