Answering the purpose of Ph.D. will help answer whether you want a Ph.D.
There could be many answers, such as:
- To earn money
- To have better life, e.g., more time to relax (not true at all! professor job is one of the busiest!)
- To invent something cool
- To get publications
- To make myself and my family proud
- To be accepted by the society
- To survive
But all these answers are secondary, the main purpose of Ph.D. is to train how to solve problems in a systematic and scientific way (not simply by uninformed intuition or one-dimensional thinking), and through this ability, you generate new, solid knowledge to our world, even the knowledge is small. In other words, you learn how to learn, how to think, how to solve problems, how to prove something, in a very concrete way. Note that a Ph.D. is not yet about solving a big problem, but rather about preparing you to solve one in the future.
It is really really difficult and Ph.D. can be one of the most stressed (and sometimes depressed) moment of one’s life (you can imagine a Kung Fu disciple trying to strengthen his body, Ph.D. can be even harder than that!). You will be surprised that your mind has many logical fallacy and inconsistencies that need to be trained in order to think logically and scientifically.
You can also receive this training via industry but it could take you many more years as you may not be systematically trained but the salary is usually much better in industry. Definitely, opening a startup/company is also a quick way to intensively train your mind because you put your life in line. But all in all, thinking deeply and critically is a skill that needs a lot of intensive training and is really really hard. That’s why a genuine Ph.D. could take as much as 6 to 8 years.
The key point you need to aware is that getting Ph.d. or doing other things have their pros and cons, and it's really up to what you really want to do. If you enjoy working with a team of smart people in a clearly defined project, industry may be the way to go. If you wish to challenge yourself by opening a startup, then it is also a good way. On the other hand, if you enjoy coming up with your own project and some grand idea, where the goal is often less clearly defined and the impact is more of a long-term, then research may suit you best.
There are some cases where research is just not for you. For example, one of my friends prefers people telling him what to do, and he can come up with a superb solution and excellently execute them like a boss (now is working at a top-tier international company). But he just dislikes carrying himself to do independent research. I also have a friend who just dislikes working in industry because he has so many new ideas and wants to try them out which the company does not allow him. Here is the key message - you got to know who you are. No one career is better than the others, all have their uniqueness, it's up to your choice. All can be successful if you are sincere to your job.