Only people who share at least one relay with you can view your notes. So, if you’re using only one or two relays, your reach will be somewhat limited. However, beyond a certain point, adding more relays only marginally increases your visibility. In fact, using too many relays can have downsides, such as reduced performance and higher data usage. Generally, more than 10 relays is overkill; with that many, it’s highly unlikely that someone won’t share at least one relay with you.