I think you actually do not have very much power as a board member. During normal operations, you can give advice to the CEO, but you have no power beyond the “access to the CEO”. If the CEO resigns or is being forced out, you briefly have an important power, but it is a very narrow power, the ability to find and vote in a replacement CEO.
The position is very public and respected so it may feel like “a lot of power” but quite often even a mid level employee at the organization has more real power over the direction of the company than a board member does.
In high school, college, and graduate school I was not very hard working. But when I left school and started working in the tech industry I suddenly became very hard working. At first, I was surrounded by hard workers who were very smart, and I was very competitive, so I wanted to be one of the best. Over time, these other hard workers became my friends, and since we were all working together on hard projects, other people came to depend on me. If I said I would have X done by the end of the week, and I didn’t get it done, my friends would be disappointed. But if I got X done and also got Y done, my friends would be excited and proud of me.
In school none of my friends ever really cared whether I got something done or not. Everyone is just working on their own thing.
Once I spent several years being very hard working I got into the habit and it became easier for me to also work hard in situations like startups where I had to rely on myself more to drive things forwards. Then, once you get good at working hard, you often want to create an environment that makes everyone else work hard, too.
So my main advice is to find a job where your coworkers are both very smart and very hard working.