I would be surprised if this argument is borne by the facts. Sure, Bill Gates would be a trillionaire now if Microsoft remained private for longer but for ever

I would be surprised if this argument is borne by the facts. Sure, Bill Gates would be a trillionaire now if Microsoft remained private for longer but for every company that sees tremendous growth after IPO, how many see their shares sink. This investment strategy only works if you are able to predict the top of the market for individual private companies which is likely incredibly hard to do. Given the power law of returns in VC, you only need to get this wrong once or twice before you wipe out the returns of your fund. As for the idea that PE firms are buying up SFH, I would be surprised if this is happening on a meaningfully large scale (anecdotes aside). Homes are real physical assets that need all sorts of actual maintenance on an ongoing basis. I don't know of any investment firm that is set up in a way that supports this type of operational burden. Even if they outsourced the work, it still wouldn't make sense to have any management overhead to keep on top of it. Investment firms want assets that can exist (for all practical purposes) inside of a spreadsheet. Homes are the opposite of that.