what is the alternative? Sure You can go Angular 1 + established UI Frameworks.
But if you are going Angular 2, then what do you use? If you use Bootstrap, then you don’t get material design. If you want material design, this is AFAIK the best framework out there.
They use all the native angular material components where possible and build on top of that. The alternative would be to build all of it yourself but that just sounds bonkers to me.