They need to sell to people so the Discord/Telegram and website need to be easy to access.
And Discord/Telegram and websites want it to be easy to make stuff with/on them. The alternative is some vetting process where you submit a form for what the site is for and then someone from an authority logs in and checks manually.
I'm under the assumption that there are groups that require reputation to join (e.g. on private Telegram) that have a higher barrier of entry than a public Discord invite.
They need to sell to people so the Discord/Telegram and website need to be easy to access.
And Discord/Telegram and websites want it to be easy to make stuff with/on them. The alternative is some vetting process where you submit a form for what the site is for and then someone from an authority logs in and checks manually.