Will paper money and coins ever become obsolete?Physical money is RAPIDLY becoming obsolete as we speak.
The vast majority of USD, Euro, Yen and Yuan only exist online now, and the physical money & coins are something that both governments and the users want to do away with but has been technically impossible to do so until now.
Now we have smartphones and smartwatches and smartcards and bitcoin hardware wallets and brainwallets and all kinds of gadgets that can interface with buyers and sellers for us, online and in person, and do so redundantly. The tech is still rough on a few but there's more promise, especially in bitcoin, than anyone even knows about here.
Consider too that we are moving more and more online to do things there that just 5 or 10 years ago did exclusively offline. Watching movies, dating, playing games, even working, we just keep finding more things to do online and therefore we are basically moving into a new phase of human existence where we slowly become infused into the internet.
...Seems pretty reasonable to me that we'd want to move our money there as well. Bitcoin was designed to be that money, it's the perfect cash for an online society. -And it's growing at an incredible rate, so I'd give it another 1-3 years before hitting the mainstream and then 5-10 years from now until we're all using it so much that physical money just stops being useful.