here's a recommendation:
if you own a 3ds (including new 3ds xl, 2ds, etc)
install a custom firmware and homebrew
and make backups of your library
it's perfectly legal to make and use roms as long as you don't redistribute them
here is why:
one day, your 3ds will die
one day, your cartridges will die
all of these servers will die
one day, nintendo will stop existing (this is somewhat besides the point, but still)
emulation is how we preserve games
and it's not just for you; sure maybe you won't ever want to go back to the first luigi's mansion
but maybe your kids will (passing down ownership, if you insist on caring this deeply about copyright)
there are so many things like this
even if you don't care about game preservation as a whole, there are plenty of personal reasons to keep at least the good stuff around
and you already know what the good stuff for you is!
the step beyond this, of course, is wider preservation, and perhaps redistribution once it becomes legal (copyright expires / nintendo goes bankrupt / library-like "borrowing" schemes that work fine for ebooks)
but I'm not asking you to do any of that
make the backups
for yourself
you can even just keep them on a bigass microsd card 😄