What happened to buying a single ticket at the station, when you need one? That's what I did when I was in Tokyo, but it was a long time ago
They're still available, but the card is more convenient(phones even more so). Tickets are also now priced slightly higher than card rides.
yeah they still have the ticket stations next to the one to refill/buy IC cards. and thanks to the 20/21 Olympics in english now too(not 2 levels of menus deep like many of them used to be) so pretty easy to do
You can do that, but the card is far more convenient and journeys are cheaper too.
If you're doing any transfers it could get reasonably complicated. SUICA makes those easy, unless you need a recharge to top it up.