I have a Garmin Fenix 6 that definitely can do this, I do it all the time. You can customize the display so that it only displays the heart rate, or e.g. the heart rate and heart rate zones. While the Fenix 6 is expensive, I think there are a whole bunch of watches in that segment at different price points that will do what you want.
I think the general category you're looking for is devices that support ANT+.
I think the general category you're looking for is devices that support ANT+.