I’m of the old school boom that learning on old school is the way to go. Then as you learn newer toys it’s easier. Going backwards... well for an old bloke like me I think I would struggle.
I flew many years on in buckets of....... Glass for a long time, going back onto an old 6 pack takes about 3 seconds for it to come back. As said above it also teaches you to think outside the square.
Nothing wrong with glass I love it I just don’t think initially it belongs. In years to come there will not be a choice!