A full-stack developer is a jack-of-all-trades, but acquiring the skills to master server-side and client-side development requires years of hard work. The world wide web is constantly evolving. As an Electrical Engineer, I know how fast technology can change, and how fast it can change the world around us. You need to stay up-to-date with the latest programming tools, trends, and workflows out there.
PHP may have its flaws, all languages do, but it is still one of the best languages for server-side scripting. I have worked with CRMs