Ruined portals never generate in superflat worlds by default

That is because the default preset does not allow them to spawn AND they are not yet implemented into superflat presets.

They ARE implemented into superflat presets, as "ruined_portal".

Is anyone still noticing this issue in the latest versions?

Can confirm in 20w49a. I've attached a screenshot.

Can confirm in 21w03a.

Can confirm in 1.17.

Ruined portals can not spawn on superflat worlds because Minecraft dose not work on it and it's a 1.16 update so it would not be updated because it's only 1.17