Assuming that the long term goal is to start a company of your own at some point they are just means to an end.
If you work at a large company you need to work for a longer time to have enough cash, relevant knowledge of wide business area (not just something highly focused), and it is a safer choice.
However if you are one of those who like to see change, cannot stand lazy co workers, and are excited about immediate impact of your actions then startups are the place to be. It is riskier, more fun, you get enormous experience in a wide domain which might not directly be related to your work. Whatever be the reason, please do not work in a startup because you think it will do well and you will be a millionaire because of it.
Also regarding: If you are not a cofounder, you will be expected do a lot of different types of work, affording you little time to spend on the particular subfield of interest.
I for one know a lot of co-founders who work their asses off and party alongside their employees. This is in my opinion the best part about working for a startup that you will never find in a large organisation. There is no-one who is a "boss". You are a bunch of people who have a passion to make an impact and everyone is focused to make it happen.
"If you work at a large company you need to work for a longer time to have enough cash" <-- how long you need to work to have enough cash depends on two things:
A) your spending rate
B) your earning rate
And in general, your earning rate is faster at a company. Again, you have to compensate for selection bias here: not all startups are successful. Even if they are large enough to have employees.
Regarding your comments about little time, I think you are confusing "no free time" with "no free time at work to focus on something else". I'm definitely not arguing that people who work for startups dont have time for partying. Definitely not. All I am saying is that, because the nature and frequency of demands is different, you generally find yourself with more time to explore your own thing at a large firm. And yes, this is coming from a person in finance, so it must be true for other industries as well :)
If you work at a large company you need to work for a longer time to have enough cash, relevant knowledge of wide business area (not just something highly focused), and it is a safer choice.
However if you are one of those who like to see change, cannot stand lazy co workers, and are excited about immediate impact of your actions then startups are the place to be. It is riskier, more fun, you get enormous experience in a wide domain which might not directly be related to your work. Whatever be the reason, please do not work in a startup because you think it will do well and you will be a millionaire because of it.
Also regarding: If you are not a cofounder, you will be expected do a lot of different types of work, affording you little time to spend on the particular subfield of interest. I for one know a lot of co-founders who work their asses off and party alongside their employees. This is in my opinion the best part about working for a startup that you will never find in a large organisation. There is no-one who is a "boss". You are a bunch of people who have a passion to make an impact and everyone is focused to make it happen.