It depends. I can tell you that (1) you don't really need it for an industry career and (2) you surely need it if going into academia. On the downsides, a PhD

It depends. I can tell you that (1) you don't really need it for an industry career and (2) you surely need it if going into academia. On the downsides, a PhD means a number of your best years spent with a lowish salary and without a clear career path forward. It can be frustrating to spend time on some open problem without being sure you can solve it properly. Depending on the exact place where you do your PhD, you may need to play some number games to graduate, like having a certain number of publications in certain venues. On the plus sides, a PhD can be incredibly interesting, if you enjoy the research of your advisor. It will also develop a number of other skills, such as networking, critical thinking, reading, possibly programming, patience, which could be useful later on. After the PhD, you will have some degree of freedom to pursue your own interests in an academic position and the pay will not be bad, although nowhere near what you would get in industry. You will be in a good position to start a company, though, if your research has immediate practical applications. In certain fields (AI, vision, systems/cloud) it will be easy to get a well paying industry job afterwards. It used to be (pre-Covid) that you would travel to conferences in various places (in Computer Science, at least), which was a nice benefit. If you do a PhD, make sure you choose a lively venue, with other peers that you can discuss interesting topics with.