I know you can ask them to help you in co-op battles. But unless you can talk to the person outside of the game, you can’t coordinate with them. Which makes them on average identical to players you ask to play with randomly.
Wow, my introverted ass wonders the same thing every time someone tells me to make new friends
If you only add people that you can trust to handle themselves in co-op, then it is better than randomly getting people who don’t know what they’re doing or quit mid battle. If you add every single person you’ve played with and can’t remember if they are trustworthy, then yeah, it’s just random again.
Alternatively, you can find people outside the game to talk strategy with and then add them as friends in game, so the friend list is still helpful there.