Granted that no one does a PhD because they want to starve, but I think looking at it strictly from an instrumentalist point of view (i.e. will this bump my salary enough to offset being paid peanuts for 5-6 years?) is not very useful. Almost anyone good enough to get into a PhD at a top tier school is also good enough to make buckets of money without one. If you want to make money, go make money.
A PhD might lead to money, but it's hardly the easiest or most rewarding way to do so. You generally finish classes after 1-2 years -- after which point you have a broad overview of problems in your field and a few more years of practice and professionalization -- and the rest of the time is just researching and pushing the frontier on a narrow, deep problem of interest. Some of the frontier pushing is useful in industry, some of it is purely academic. If you finish the PhD and aim for a tenure track position or a few postdocs, you can continue that type of work. If you exit to applied industry, the type of problems you'll get to work on are very different.
I think you should consider a PhD if you enjoy tinkering with problems and pushing your intellectual boundaries, don't particularly care about money, and can see yourself spend several years grinding at something to produce what amounts to a book on the subject (note: a real book, not a "57 Tips To Make Sites in React" ebook to plug on medium blog posts)
In terms of whether companies are bothered by people who have too much education? Sure, some might. Certainly a PhD is not prepping you for the kind of work conditions that exist in tech startups. There's no reason to believe a PhD will be notably better at a problem than someone with an MS in the same field, and if they have 5 years less real-world experience, then there's that consideration too.
You do a PhD if you are truly passionate about the work. You do not do a PhD for money, for admiration, for anything else. You do it because you have to know something about something, and you have to know so much about it you discover something no one else knows about it, no matter how small.
There is absolutely no other reason to get a PhD because while there are lots of perks to a PhD - traveling, meeting people who share similar interests, interesting career opportunities, autonomy, collaboration - etc, you can find all of those perks at a different job that isn't so intellectually demanding. The one thing no other job can offer you is proof that you discovered knowledge that is actually new (or whatever way you want to phrase it, there exists no other institution outside of academia that is rigorously structured to ensure you don't get a PhD without doing this at least once).
You can say this is an argument of authority controlling a body of knowledge, I am sure that will be the typical start-up perspective. Unfortunately, a start-up's bottom line is to produce a product. That means that if it comes down to the mark of determining the integrity of some knowledge, or keeping the business running, the start-up is not going to destroy itself for the sanctity of knowledge. Plenty of PhD students, however, do!
You literally will have no life besides your work if you pursue a PhD. There is zero reason to do one unless you have this drive.
A PhD might lead to money, but it's hardly the easiest or most rewarding way to do so. You generally finish classes after 1-2 years -- after which point you have a broad overview of problems in your field and a few more years of practice and professionalization -- and the rest of the time is just researching and pushing the frontier on a narrow, deep problem of interest. Some of the frontier pushing is useful in industry, some of it is purely academic. If you finish the PhD and aim for a tenure track position or a few postdocs, you can continue that type of work. If you exit to applied industry, the type of problems you'll get to work on are very different.
I think you should consider a PhD if you enjoy tinkering with problems and pushing your intellectual boundaries, don't particularly care about money, and can see yourself spend several years grinding at something to produce what amounts to a book on the subject (note: a real book, not a "57 Tips To Make Sites in React" ebook to plug on medium blog posts)
In terms of whether companies are bothered by people who have too much education? Sure, some might. Certainly a PhD is not prepping you for the kind of work conditions that exist in tech startups. There's no reason to believe a PhD will be notably better at a problem than someone with an MS in the same field, and if they have 5 years less real-world experience, then there's that consideration too.