+1 - A Progressive Web App would be a welcome addition.
As a paid SAAS product, I’d expect that you’d eventually have native Windows, Mac, iOS (phone/tablet), Android, Web Mobile, Web Desktop/PWA, and a fully open API. Additionally, distribution on multiple android stores if an Android version is released.
As we pay to use your product, I believe that means meeting customers wherever they are at within reason. Sure, it is expensive in terms of R&D budget as nobody wants to maintain that much code. Using flexible languages / frameworks such as uno or xamarin helps.
As both a former Apple employee / Mac user who now prefers Windows and uses both, I know firsthand embracing everything is good for keeping active users active. The apps I use most work everywhere.
Its good for business too! Imagine if most paid users signed up on Windows and you got to keep 85-95%? That’s leaving money on the table. I’ve quit Apple, I suggest you try it too.