I love trains, model trains, etc... But!!! With model trains, you eventually end up with a layout that becomes static, takes up a huge amount of space, and zero replayability... What's really the point?
Live steam is different, the trains themselves require maintenance in a machine shop, and you can travel around the country visiting other layouts.

Home shop machining on the other hand is an unlimited sandbox, that does not end up like a model train layout.