For 1), foundational skills don't help at all apart from being able to solve LC problems. For me solving LC is a breeze but then they ask if I know their favourite stack and how well I know it. Now you need to know React, Redux with online non-trivial project in that to even be considered for interview. DB indexing is a common question as well. Web security pops up as well.

In my opinion just focusing on React/Redux is a lot better than review of algos and this is for no-name companies as well.

The thing is for tech jobs you really need to know a lot. Algorithms don't cut it anymore unless you went to top 10 school and can secure a FAANG interview where they only ask those.

The skill inflation is real. It gets more and more competitive. Nowadays they expect you to hit the ground running.

This is for junior level.