The biggest advantages of bitcoin commerce is that it's natively global and it enables a more seamless user experience -- no linking bank accounts and there's less reason to require registration/login in general.
The challenges are many people who hold bitcoin still aren't comfortable transacting it. The wallet, etc infrastructure has a way to go to lower the barrier but it's mostly people just going through the motion 1 time. Good thing is when they do, it's a magical experience.
Another challenge is many people don't WANT to spend their bitcoin (for good reason). So bitcoin does not make sense for many commerce categories and I don't expect that to change soon. The categories that do make sense so far:
special items that the seller will ONLY sell for bitcoin (art) digital items that are also transacted over Bitcoin (Rare Pepes, etc) micotransactions that aren't practical over fiat rails (stacker new for example) items that are priced lower because they're only available for bitcoin -- this is what we're testing at satscrap.com