BRO WHY DID THEY CALL LITERAL METAL SHEETS ADEQUATE ARMOR??!?!1!?11?!

It was adequate against rifles and some cannon fire. Tanks made a lot of progress over the years, as did other weapons.

They weren’t that great at the start. The engines (at least in the British and French ones) took up like 60% of the vehicle. You had to use hand language to communicate because the engine was so loud. It was also quite hard to breath because it was quite literally a moving metal box.