I've run an online community since the late nineties. It's certainly presented increasing challenges over the years.
There are problems with gatekeeping. Do you gatekeep in advance so that nobody can get in, or gatekeep after based on the opinion of a small set of moderator values? Bearing in mind that all power corrupts.
I encourage my community to set it's own standards, with tolerance at the forefront of it's values. If there is an issue to address, in veracity, tone, or behavior, take the time to address that through polite argument.
Take the responsibility to help create the community that you wish to be a part of. Don't leave it to others to impose it on you. A community is always better collaboratively setting it's values, embraced with the consent of it's members.
People are wrong all the time. I know that I am. This is rarely bad faith, but often an opportunity to expand understanding, and share a different perspective.... if people are prepared to tolerantly help, rather than stand by.
Think well of others, and yourself, and build something everyone can be proud to be a part of.