Apple are always used as the example of why design is a crucial differentiator. Having a well designed, easy to use product is regularly cited as why something is better than a competitor.
That was true in 2007 when comparing the iPhone to other phones.
It was true in 2010-2012 when comparing SaaS products to their on-prem, enterprise alternatives.
It’s not true today.
Having a well designed interface with consistent styling and a well thought through user experience is standard.
Consumer products are always a few years ahead of business products but even with SaaS products in 2018, poorly designed products only stand out because they’re now so rare.
It’s certainly not that creating good design is easy to do - it’s still just as hard as it always was. It’s just that customer expectations have changed in the same way that everyone expects “mobile” to include iOS and Android, websites have to work on all major browsers and public cloud infrastructure is the default.
If you find yourself focusing on your product being “beautiful”, “easy to use”, “design led” or leading with “look and feel”, you may need to rethink your competitive positioning.