We heard your feedback when it comes to the user experience in the Azure portal:
Blades are not ideal
Horizontal scrolling provides a bad experience
Different create experience for different Azure services
With your feedback, we're redesigning create experiences across the Azure portal to make better use of the screen real state and to offer a simpler, standardized experience. One of the services that now leverage the new create experience is Azure App Service.
Have you seen the new experience for creating Web Apps in Azure using the Azure portal ? Check it out in this 5-minutes video: https://youtu.be/dHTzv-zY17I