Yep, as in all things, we do the easy thing until it stops working. Only then is it worth putting more work into harder things. I’m not deriding this approach,

Yep, as in all things, we do the easy thing until it stops working. Only then is it worth putting more work into harder things. I’m not deriding this approach, mind you. It’s efficient. Edit: Also the incremental improvement over the current system needs not only to be big enough that it outweighs the cost of the changeover (including hidden costs like risks and opportunity cost), but also to be big enough to bother with in absolute terms. Things like zip, mp3 and jpg are good enough that even though there are now alternatives that are better by any reasonable metric, for most users it's just not worth the bother of changing over.