A good discipline to get into with regards to any form of sales or account management:

*Write down* "If we lose this deal, it will be because of X." in advance.

If you lose the deal/account/etc, ask why you lost it.

Check against your prediction, and get better at predicting.

This naturally applies to e.g. seeking investment, trying to hire someone, trying to get a job, etc etc.

You write things down in advance, ideally with a confident number attached to them, because it defangs the risk of 20/20 hindsight and helps you synthesize insights.

"Looks like we were correct over 80% of our time that in competitive situations with AppAmaGooBookSoft candidates would explicitly cite total comp as the reason they are declining to take our offer. OK, that's reality. What strategic decision do we make now that we know it?"

Conversely, if your sales team writes down "If we lose this deal, it will be because of the cost" and the customer literally never says "It was the cost", a) fix the actual problem and b) time for a chat with sales about not discounting so much, thank you, really not helping.

"But Patrick, sometimes people don't tell me the reason the deal didn't get done, or don't accurately introspect why the deal got done, or aren't candid about why the deal didn't get done."

Yep we're playing a game with partial information, but that doesn't mean total ignorance.