And that's it. Are there any uses that I'm missing?
Ability scores also make half-feats viable.
If you use the DMG variants for auto-success the ability score is used vs the DC in formula for determining auto-success.
In essense, with different math, it establishs a low dc "auto-success" based on score with the ability check for higher possible gains.
This is very similar to how jump is treated and imo provides a good consistency between ability scores, checks and DCs.
Chapter 8 Role of the Dice Variant Automatic successesThanks I will look into that. You wouldn't happen to know that page number would you?

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.