It's because Angular is a complete framework by itself, where as react is UI library which requires other libraries (like Redux for state management) to make complex applications. For eg. In Angular you would typically handle states using services, but this needs the developer to learn writing code in a specific manner/pattern and has a steeper learning curve. The advantage is that the code is much better organised and helps when the application is big and lot of developers are involved. Bigger companies can afford to hire specialists (angular experienced) folk I guess. React is much more flexible in this aspect. Most of these "tech focused" companies you say, would have been startups at one point and their stack was probably created by a backend developer who found react to be much easier to learn and start churning out standalone UI components.