Good filters make good communities. Back in the good ol' days of the internet, access to the internet in of itself was a decent filter: you had to want to be online, you needed to be somewhat technical, or at least willing to grapple with technical problems, and you needed to actively seek out communities online which aligned with your interests, and there was little financial motivation to do so in bad faith. As the barrier to entry to the internet writ large dropped to near zero, communities that were built around the bygone era's natural filtering suffered. Communities must now establish filters proactively.

Ultimately, you need to choose: does your community prioritize its short-term health, or ease of access? If a community never lets anyone in, then it withers and dies eventually, but in the meantime the community can be extremely high-trust. That's what happened to fraternal orders like the Oddfellows and the Free Masons post-Vietnam. If the community has zero barrier to entry, you end up with Twitter: a teeming mass of low-trust members screaming into the void.

The happy medium is allowing in new members just as fast as you can build trust and community cohesion. University clubs are a good example of this: at a massive turnover rate of 25% per year, they need to form processes to not just recruit that many people, but integrate that big of a chunk of their community without destroying the high-trust environment. That's how you end up with the ritualized "rushing" process.