A little bit more is a giant understatement.
The Rage 9 game engine is a giant leap forward in many underlying video game systems.
Rage 8, which powers Red Dead Redemption 2 was basically just a prototype test bed for GTA VI.
Obviously we'll have to wait and see what all actually works and got integrated in VI, but consistently the numbered releases of GTA since III have redefined what is possible in gaming and game engines.