How to get upleveled

I've seen offers of people getting upleveled across companies at similar tiers, FAANG to FAANG, or MULA to other top pre-ipo places. But why would a company uplevel? Like you can talk about all the scope and impact, but why don't the interviewers think, if those were true, why weren't you promoted?

I just want the secret to convincing the interviewers that you are performing at a level above your actual level.

Blind tax: 300k