Chrono Trigger is still being sold actually, so probably not the best example. That said, I still have my original PS1 Chrono Trigger disc that I haven’t played on original hardware (or even my still-hooked-up PS3) for a while because I legally dumped it and play it with a much higher emulated disc read speed. As much as Nintendo has made explicit statements to the contrary, it is legal in most countries to back up your own games and do with them what you will.