What keep all those robo advisor company to be floating instead closing down

People want to invest but dont know how. So just put $$$ in robo + some people no $$$, can only invest $50 per mth, low barrier of entry.

Robo will remain relevant. As there is always people dont know what they doing + low budget.

Convenience

Despite the lower brokerage fees in the industry, the barriers to entry to DIY investing are still relatively high. It is less intimidating to invest through a roboadvisor that recommends a diversified portfolio based on your risk profile. It is a more fuss-free option for those looking to get started but do not have a lot of time to fully understand terminologies like ETFs, stop-limit orders, etc.

Low Fees

Traditionally, besides DIY-investing, the alternative would be to go through a bank or an insurance company. On top of the fee you're paying to the fund managers, you'll also be typically paying other fees such as wrapper fees to the distributor. They are especially higher if the funds offered are actively managed funds. Compared to these other alternatives, roboadvisors provide a much more cost-effective solution. The underlying securities used are also typically low-cost ETFs or unit trusts.

Hence, the way I see it, roboadvisors have a strong selling proposition, with a sizable target market - working adults, retirees, and even HNWIs - and I don't expect them to go away anytime in the future. That being said, it is still possible that some may close down due to the competitive nature of the industry, as evident from Smartly ceasing its operation.