It's also highly speculative so like I'm not going to go back and forth on it.
Needing a vendor to hand hold your likely highly paid dev seems like a bad fix to me.
Also not having an index isn't an error it can be a valid choice based on your situation and query load which is why people should know the situations when they're needed.
I think people should simply be better. A lot of people don't like hearing that though so usually I keep it to my private chats where people seem more willing to cop to that fact.
I know we disagree, I know you're going to continue disagreeing, I know I don't want to have the conversation.