Its content creators that move masses. And if those do not move nobody will. I've had Bluesky for about a year now and pretty much abandoned it some months ago because only like 5% of the people I follow post/crosspost to Bluesky.

In Discord's case its mainly project wikis, forums and video game focused servers + their admins that should move. If they remain on Discord everyone will keep on Discord.

I myself am within multiple servers (that are strictly non-pornographic mind you) that due to the main content/game/media they focus in and the social behavior they cultivate, will most likely be rated non-teen safe.

Most shooter games are Rated R/PEGI-18 f.e. and they have tons of big Discord servers.

However, as I have seen in my country Australia under the new social media ban, our Government has mandated social media companies to use age verification technology. As part of this they have mandated that Government ID verification cannot be the only method. As such the social media giants have implemented age verification technology through the type of information you have posted on your account and potentially facial scans.

I struggle to know what else these companies can do if they are mandated to implement age verification. However, they should not be storing Government ID, there should be a broker.