Occasionally in YC founder circles a new founder will raise a bunch of money and then ask something like "What's the best way to invest all the money our company just raised?"
The responses are always along the lines of "Your startup is already risky. Don't innovate in areas of your business where the status quo is known to work. Innovate your product + technology, don't be innovative with your company's finances, HR, etc"
That advice always stuck with me. It just makes a lot of sense to do things in the most boring way possible, except where it matters (your competitive advantage <-- that's where you innovate, that's where you set yourself apart)
Running a startup is distracting enough. Doing things non-standard just adds to the list of distractions that you don't need as a founder.
The simplest explanation is that this is a mostly symbolic move: They want to show that the stable coin and crypto companies they invest in are actually trusted by YC. It starts to look hypocritical if an investor is funding crypto companies and praising them as important breakthroughs, but not actually using them where it’s important.
Break in, bash owner about with a wrench, get coins. <Insert xkcd>
There are ways to prevent this. Like using multi-sig with geographical separation (so you can't move funds alone) or setting up forced time-delays. Ultimately, being your own bank is a massive responsibility, and I think too many people take that reality too lightly.