Me: Hi Garmin, the strap on my partner's vivosport has snapped.
Garmin: Sorry, you can't get new straps - it's an all-in-one device.
Me: Oh, that's disappointing.
Garmin: I know. Anyway, we'll send you a new one.
This is is similar to my experience when the strap on my vivosmart 4 broke.
Garmin might be overpriced and sometimes a little bit shonky but I'm a big fan of their regular software updates (even on older models) and pretty decent approach to repairs and replacements.
Very similar to my experience with Fitbit "Charge HR" and it's ballooning straps... Replaced 3 times or so with brand new devices, before the warranty was over.
Me: Hi Garmin, the strap on my partner's vivosport has snapped.
Garmin: Sorry, you can't get new straps - it's an all-in-one device.
Me: Oh, that's disappointing.
Garmin: I know. Anyway, we'll send you a new one.