What is the advantages of robo advisor compare to asset allocation ETF (e.g AOA) that having much lesser fees?

Robo-advisors generally tries to be your trusted advisor. They do webinars, "market updates", holds your hands when markets go down, and you can have multiple different "portfolios" through one single-login, and with the spiffy interface most of them have, you can't beat the ease of use. ETFs, in general, even AOA ones, involves some level of DIY. first you got to find a brokerage, and manage the entire registration process, which may or may not be as easy as the robo-advisors. Then you need to physically press "buy", and decide how many (not that many brokerages have the easy-button of "use all my money in the account"). Robo-advisors, again, like your trusted advisor, will help you "rebalance" your portfolios (generally subscribing to the belief of "reversion to the mean"), and also tax-loss harvesting (not so applicable in Singapore). Rebalancing between different ETFs on your own is a little tedious, involving buying and selling.