My question is: who says you can't be left out?
Some people have a sense of entitlement that would have baffled and offended previous generations, especially when including you means excluding 100-times more people.
Everyone cannot be included in every single thing. Be okay with that. It is okay to be left out sometimes. Select your battles carefully. Going up against millions of people, with your tribe of hundreds, may not be the best use of your time or energy. Instead, work on growing your numbers organically so you don't have to battle to be included.
You could be invited instead. There's a difference between forcing your way in and being welcomed. One has short-term impact, while the other has greater long-term effect. Which matters most?
And another thing...
If/when you do get invited, be gracious. That's a topic for a different day.