The inflows will come once the ETF or companies with a lot of BTC are in mutual funds and etfs that are put in retirement accounts then people will buy BTC every week or two without much choice pushing demand though the roof depending on how many peoples retirement plans have BTC embedded in it. That will be a bit money maker for banks bc they will charge some high expense ratios, not offer any defi returns and offer no way to really cash out for many many years stabilizing BTC and ETH a lot once more and more enter these vehicles.