If you want high salary potential of FAANG and want to go there, then you'd have to be good at algos, regardless of if you have 1 year exp or 10 years exp and Fullstack expert. So you can skip the unrelated part and just learn algos and get in at the start of career. If algo is too much you can apply everywhere else but instead of algo you'd be tested on other skills. Reason TOP companies don't test open techs is because they have internal tools they use so they can't test people on things nobody would know on account of not being in the company. So they test on something very general and innate to programming.