You'd still need to take a day off for Google to grill you on algorithms in person. I don't see how taking a day off to work on interview problems independentl

You'd still need to take a day off for Google to grill you on algorithms in person. I don't see how taking a day off to work on interview problems independently is any different from that perspective. What the latter offers that the former lacks is the opportunity to work on it after hours without affecting your day job at all.