Having money does not make you wealthy. Having the correct financial arrangement to consistently make more than you spend is what makes you wealthy.
ADDED: Yes, you're "rich" but not jet-setting in business class at resort hotels, multi-million dollar coastal city condo, eat at top restaurants on a regular basis etc. rich. Which is actually just fine for a lot of people who have no particular interest in those things.
Nothing is guaranteed if things go totally to hell, of course. (And I did make the qualification of not being pegged to inflation.) But unless we get to a very bad place, I think that assuming 5% on these sorts of investments is a pretty safe bet.
(ADDED: But pick your own number. 3-4% probably is closer to the really very safe modulo inflation given instruments like CDs in that range. But you're reinforcing my basic point. $2M is not really the basis for a huge annual income in perpetuity or even over a multi-decade timescale if you don't have other income streams to add to that mix.)
Past performance does not promise future results, and the world could end tomorrow, but it's not a bad idea to plan that you'll get an average of 5%+ on market investment.
(I'll note that you're responding to someone saying "pretty much guaranteed" and dropped that qualifier in your question).
That said I think semi-retire is the best bet. You have $30,000 for existence, and then go and do a gig every now and then for that foreign holiday or home repair or whatever.
Consider checking your prejudice at the door.
Anyone with a couple $1000 can buy cheap etfs or index funds
In fact, isn't that basically the entire premise behind all the VC funds that fuel Silicon Valley?
Which often don't have especially high rates of return.
I don't really disagree with your basic point. At least somewhat higher investments do give you access to a wider variety of financial instruments even if diversified through a third party.
To be very rich requires upwards of $100 million. Then you can access high paying investments which will generate enough income to afford a couple houses, hire help, buy a boat and a plane, and have enough left over after taxes to increase your assets to offset inflation. Actually, if you want a jet plane (with hired pilots, mechanics, hangers, etc) and a couple nice houses (>$10 million each plus staff) in the nicest places (Beverly Hills, Palm Beach, Jackson Hole), you need upwards of $1000 million.