Ace Combat is many things, many awesome things, but it's not a replacement for Crimson Skies.

You could give Project Wingman and it's DLC a try, or maybe track down a copy of HAWX? Star Wars Squadrons? Tonally, all 4 games/series are wildly different, so you kind of have to narrow down what particularly you liked about crimson skies beside the gameplay loop: the story, the themes, the lore, the music, etc.

EDIT: This video may help: https://www.youtube.com/watch?v=8Zr67YFN--0