don't let bro know that us PC users have had it for years
hi, non-fangirl apple user here!! it’s very much not needed to upgrade every year. the yearly upgrades are very incremental now, but if you wait on an older model before upgrading its more worth it. coincidentally, three years is probably also a good timeframe, but you could definitely go longer
now, i’ve only had experience with the series 3 (and a small bit with the SE) but imo it’s 100% worth it to upgrade. you’ll still be able to use the watch with the phone obviously, but everything is just far better on a device actually meant to be your main one