The point is not to say all is lost so fuck it, but to highlight that maybe there are systemic issues with an unregulated free markets. Networks have consolidated into a handful of streaming services to a point where there are really no other options for consumers.
What are you going to do? Read a book? Go back to DVDs? They can afford the relatively few people willing to take an all or nothing proposition to squeeze consumers for all they got. They are also really good at lobbying to keep the law on their side to keep it that way.
Speaking as a designer, it’s important to separate the style/trend of a UI from its function. I think what you’re looking for is actually UX design.
As a discipline, User Experience uses evidence-based research to understand how and why users behave they do. This leads to specific design patterns and principles that underlie all the good UI design seen from the giants like Apple, Google, Microsoft, etc. It gives you the language to evaluate designs. This is the foundation of your UI and the rest is just style — fonts, colors, imagery and icons which is subjective and less important. I lost ambition to be a trendy UI designer, so every design looks the same, but usability will shines through. Clean, simple and accessible is timeless.
Study the articles from nngroup.com. They pretty much established the field of UX Design, with content talking about user behavior in the 1990s. https://lawsofux.com is a more attractive and consumable option, also heavily influenced by NN Group. Finally, accessible design is good design for all, not just those with disabilities. Understand the guidelines set by the W3C for accessibility, like minimum font sizes or contrast ratios for colors.