Client side is only interesting in complex generic reactive programming problems, state machines, domain modeling in the client, local first patterns. The part about browser or mobile platform intricacies is very lame.
Coding and algorithms are just some of the tools available for frontend and software engineering. UX is another layer that most software engineers can't grasp, it involves art, sociology, politics. Calling it boring and unimportant when you are not good at it is a misunderstanding of software's true purpose.
No one even mentioned agorithm. If you are really user focus as you claim to be, you should love cross platform, focus on delivering values and not be a simp for these "native" tribal knowledge. Talking about misunderstanding software's true purpose.
Obviously I love to reduce front-end to generic problem solving and abstract the platform aways which contradicts directly with your amateurish "looks ma how minimal and artisan my html & css are".