I am sure many investors look to invest in companies that they understand, so they can leverage any expertise they have to evaluate why this startup is the special snowflake that will make a gazillion dollars.

If a startup has insane metrics but you don't "understand" their secret sauce, it may still be a sound investment, but I imagine you'd ask yourself if it was too good to be true, or due to temporary conditions, or rigged data, or something else, since you lack the expertise to understand why the numbers are so good.