STOBAR isnt a huge upgrade from STOVL really, but going CATOBAR would have made for a significant upgrade.
India has actually launched an indigenous 40,000 ton carrier, not a refitted Soviet ship.
Funny thing about carriers though, when you need them, you NEED them.
Without US supplies, NATO would exhaust it munitions in a matter of days., and NATO is very dependant on US C4ISR and EW assets.
110kt, while powerful, is not that powerful. The UK and France combined is getting closer to MAD capability, either one on their own is not capable of it.