PrimitiveTechnology didn't stall out at mud bricks, he's literally built a waddle a daub house which you see behind him, and he's using a turbine pump to blow air for metal smelting. he's extremely successful at everything he's aimed to do
It’s fun to read goofy guides written for time travellers visiting the past that describe how to reinvent things like penicillin and powered flight while also watching the struggles of a man in the outback trying to reinvent technology from scratch but stalling out at mud bricks.