Because Quirks really ARE that quirky.
Your Quirk is called 'Starter'. It might not sound like much and, compared to some of the others in the family, it's weak but it has far fewer drawbacks than the others in the Clan.
Yours is the ability to summon any trio of Pokemon that fall under the 'Starter' label. You only get one of each and you can't pick the gender, nature or abilities of your Pokemon beyond what they can learn but you still think your Quirk is decent. You can only summon them in trios and none of them can breed but 'eh'.
At least you can keep yours around nearly all the time if they were in their first Evolution.
There have been so many, many, many Pokemon games since the idea was first developed. It's going to be a long, long time before you run out of partners to train.
None of yours can go Mega or do Z moves or any other of the gimmicks the games came up with but that's fine. You don't need them too.
It's sort of annoying you can mix and match which of any particular trio you summon but that just means you'll have to train harder so you can summon three sets of baby starters, two sets of baby starters and a mid-level starter or one baby starter and one set of fully evolved starters.
You want to be a rescue Hero even if your clan usually hires out as specialists.
Your Clan probably won't approve but you DON'T CARE. You want to help people more than you want money despite the fact you don't want the Clan mad at you.
Some of the others in your Clan have Quirks called 'Legendary', 'Mythic', 'Time', 'Altered', 'All Waters', 'Mega' and so on. It's not hard to pick what they do though Mega only works in tandem with someone who has a Pokemon capable of achieving that form. Their Quirk is useless by themselves.
A good rule of thumb was the more powerful a called Pokemon, the more energy it took to Summon it and the more exhausting it was to keep the Pokemon in the real world.
Others of your clan have Quirks like 'Jenny', 'Joy', 'Pokeball', 'Berry', 'Egg', 'Candy', 'Type' and so on. All in support of those who had a Pokemon Quirk.
The Clan had made it their specialty.