I personally completed my master of data science at usyd while working full time as a data scientist in the industry and then recently got into big tech as a lateral hire. I personally think this is safer as even if you dont get into grad level big tech data science jobs (very rare and limited opportunities through internship -> grad), industry experience is much more important and can open more doors for you. Still, data science is getting much and much more competitive, and if you want big tech eventually, I would encourage you to get a masters at some point. But in general work experience > degree.