You can't hold on forever on that one brilliant invention, you're expected to break even (or make huge profits) in about 25 years.
That is, unless you're a singer, artist, writer or someone else belonging to that select group, which can do one thing and get paid for it 75 years in almost every country and 75 years is like forever in a human life span.
I prefer to stay with original lego, since they fit very well but some new normal cloned bricks might fit just as well, I don't know, haven't tried them nor I am intending to do so. But most people tend to agree that lego has the better quality bricks (is there some a secret ingredient just like in coke?). Unless you get the outsourced chinese ones, they're not an par.
I would love some competition to get some better affordable lego prices.