I wasn’t impressed with the legit Garmin leather one that I got a couple of years ago. Nor have I managed to find a decent aftermarket one.
However, I’ve just got one of Garmin’s Jacquard-weave nylons straps to go with my fancy new Epix, and whilst the price was utterly obnoxious, it’s really nicely made. Thick but flexible laser cut fabric, and very nice stainless steel hardware.
Got it from First Class Watches, and used their “Make an offer” function to get a fair chunk off.
https://www.firstclasswatches.co.uk/garmin-quickfit-22-marq-black-jacquard-weave-strap-only-010-12738-21-p-59165/