Take a look at the randomized worlds in Grow: Song of the Evertree

https://store.steampowered.com/app/1380420/Grow_Song_of_the_Evertree/

Feels like Grow has a similar concept in creating random worlds, except there is more of a sense of wonder and even fae vibe than Nightingale's Realms. Player actions directly impact the look and evolution of each world.

Again recommending random Realms be smaller, maybe featuring one or two major landmarks so that it'll take several Realms before the player has seen "everything" (i.e., every type of landmark).

Also landmarks can be in different configurations, such as sometimes just one statue, other times a whole bunch of statues perhaps in an intriguing pattern.

Re-use assets in different ways and possibly add interesting scripts to some of them. This lets you have more landmarks without as much work trying to make completely new ones.

Mix and match plants and colours and scaling and weather intensity / range / volatility and whatever else to have a wider variety for more possible combinations even within each biome. Grow: Song of the EverTree allows randomizing worlds using 3-5 out of 25 Essence influences, plus each world has another 5 "rare" Essence influences. This results in a much wider and more tangible randomization that Nightingale's three biomes.

Smaller realms with POIs closer so there's not so much tedious running through empty land. Hogwarts Legacy also does this with dense POIs so there "always something to do".

By using a learn-by-trying-to-make tech tree and making essence primarily used to craft magical items like realm cards and minor cards, we can enhance the importance of cards and make adjustments to realms more meaningful and less of a way to simply make the realm easier for whatever the player is trying to do, e.g., material yields.