Another reason not to ask the most experienced person you can find is that it's likely been a long time since they've approached their domain from anything near

Another reason not to ask the most experienced person you can find is that it's likely been a long time since they've approached their domain from anything near your perspective. They've deeply internalized complicated abstractions and terminology that you might not have even been exposed to yet. By asking someone with less experience they're more likely to understand what you're asking for and be able to explain it in a way you can follow.