Well, crypto is rarely low volatility and ethereum moves like crazy, but it is still decent, it is basically all he asked for. Sure there is nothing in the world based on a company that I would trust, no company would be good about how "we put money in, it gives us 10% back yearly" type of deal, it is not possible and that is why I think it is quite obvious you assumed something like that, but when it is ingrained in the system like proof of staking that is something definitely possible.
You got a good point there, ETH 2.0 is going to launched as far as I have heard, not yet confirmed as to when in 2021 or 2022.
As per the article on Cointelegraph (not that I am a fan of these sites but just for the sake of reference) -
https://cointelegraph.com/news/when-will-ethereum-2-0-fully-launch-roadmap-promises-speed-but-history-says-otherwisethe launch might take a couple more years from now.
Now this is not the first time I have heard ETH move from POW>POS method and this has been criticized a lot. I have been hearing this from 2018 IIRC, on many internet chats and trollboxes.
I would defenitely like to see if what the OP says becomes reality with ETH 2.0 but I am skeptical because of past experience and observations on such schemes.