For humans it can be things like going to college, getting a computer science degree opens a lot of door so it is good even if you don't plan to do anything specific. Similarly as a company founder you can just try to do things opening doors, like Google focused on making a great search engine because they believed that having the best search engine would make all other aspects of the company easy.

You could say that focusing on areas which will give you more options in the future is a plan, but I don't think that most people see it that way. For example when you ask a kid why they go to college and they answer "I don't know what I want to do, I'll just study something interesting and see where it leads" you'd typically not say they have a plan. Yet many of them still go on to get valuable degrees and succeed in getting a much better job than the average person.