Depends on the board. My current one is tall, so yes. I get wrist pain without one.
I think it is always personal - they are actively bad for some people, causing more strain. You have to take ownership of your own ergonomics and figure out what you need, and the answer also involves your desk, chair, how you sit, how you type, how much RSI damage you've already done, and frequently how stressed out or otherwise unhealthy you are.
Specifically wrt wrist rests, experimenting is really easy. It is just a hunk of mass; what you pay for is aesthetics. Look around your house and dummy something up. If you have access to wood tools, a two by four, sandpaper and nearly any cutting tool it is all you need. If not, find something slightly smaller but approximately the right shape, angle it, and perhaps put some cloth over it or something. Type on it for a while, see what happens. Adjust as needed. Perhaps experiment with something squishy on top; that seems to work for some people.
Good luck!