Going by the thresholds above (I don't know that they are correct), sitting on $10M in assets would require a 7.5% annual income return to reach the $750k thres

Going by the thresholds above (I don't know that they are correct), sitting on $10M in assets would require a 7.5% annual income return to reach the $750k threshold. That sounds very unlikely, if the person is living on passive investment income. Even with a well-performing stock or real estate portfolio, to have that level of returns you are mostly talking about unrealized gains. Those would not count as income if someone is living in equilibrium, growing their assets over time. You would only realize those investment gains as income if you were liquidating your assets to fund a lavish but limited duration lifestyle. Edit: noting your addendum, I guess we're looking at the difference between a technical implication (you must have this income if you have these assets) versus a behavioral trait (most people don't live frugally or complacently with big piles of assets)...?