How's a "2-3 year cycle" sensible or sustainable?

Who's forcing you to get every upgrade every year?

The yearly releases make a lot of sense for everybody, because then you can upgrade on your own schedule, instead of delaying the upgrade because the product was released a full 2 years ago, at a time your older one is on its last breath.

In fact, yearly releases are then also more sustainable, too, since the purchasing would be spread out to each year (on an as-needed basis), instead of having a month-long cycle every 3 years, necessitating the extra infrastructure all along the way (from the stores to manufacturing to shipping).