I love Adobe products and have been using them for 10+ years but This article seems more like a puff piece instead of an objective comparison.
Both are great for different user needs and team workflow. XD+Photoshop is good for building prototypes of apps that require heavy photo retouching and mgmt of photo assets when working with photographers. The lack of micro UI animation capabilities is disappointing, especially given the Adobe has the best video animation tool on the market(After Effects)
Sketch+Flinto is great for prototyping apps that require more complex animations and micro user interactions. Not to the level of After Effects. Flinto seamlessly integrates with sketch, screen updates and asset changes are swift. Sketch falls short when it comes to photo-retouching, even basic effects such as outlines and fades are difficult to execute.
Your last piece about Adobe being managed by a ton of resources is precisely why they were unseated by a small team of underdog developers and designers(Bohemian Coding and Sketch). Larger corporations have more bloat and find it harder to switch gears and focus on features that matter to the end user.
