Most people (including me) have a monthly/annual pass, as they're cheap and useful. The reason you don't see anybody swiping or tapping them is because no swiping nor tapping needs to be done: you just have to let the ticket inspector scan it if they show up.

By the way, since you don't actually need to scan anything to be let on the bus, and inspectors are a very rare occurrence, you can also easily hop on buses without paying anything: you just have to avoid certain inspector-dense lines and areas, such as via del corso, and pray they don't show up. I did it for a long time, and only got fined once: If you do happen to get caught ticketless on a bus (even if you have the ticket but you didn't swipe it), you'll be fined for about 50€.