Very rich people have access to borrow against their investments so they don't have to sell (and trigger taxes).
I would never use FC as it is. BUT if you made a product where you never sell the underlying assets, and instead offer a 0% loan against them when i withdraw (and take a fee somewhere to cover), I would be very interested. Ideally, it might have protections so i can never get a margin call and be in debt during bad market times. Perhaps i can only borrow against the invested amount (or eg 75% of it), and any asset growth is profit, and not borrowed against.
The benefit to this is great. I can watch assets grow, and capture their growth and not deal with taxes, while still benefiting from liquidity. For people will large, regular income (eg. SDEs), you can usually rely on a continued income stream. I am fortunate that i usually invest a large % of my income (sde DINK yay), so being able to only "borrow" against a subset of it for faux-checking seems fine.