Wow...I loved it and also use to build plywood and concrete tanks. But I found them to have weakness's like all materials have. Both glass and acrylic aquariums need to adhere to basic structural rules. Cel cast is certainly stronger than welded. (Or is it? Another discussion) And silicon seals have held up for decades. Lead free glass is deluxe but heavy and really expensive. Doing anything but flat surfaces and glass gets crazy expensive. With an exception of some factory made glass tanks that have no seams. Regular glass is too green for anything but pretty shallow tanks.
It goes on, everything is a trade off.
As to plywood, never came up with a coating that would hold up like glass or acrylic. The glass to wood seams were also sometimes a problem. But they were cheap and held water.
I bet you love old wooden sail boats?
I think Mr_X was also a fan of plywood and even concrete tanks.