i don’t disagree that there are better returns to be had, and someone with more knowledge can have them.
Look at what the Robo-advisers are targeting however. People that have built up some cash savings, and are looking for better returns but do not know about funds or shares how to go about it. You can easily get a half price fee’s over (mine was £15k free for a year) when i signed up, and then a few referrals since then have kept it free). I am now getting far better returns than what my cash savings, with minimal effort.
Sure as i monitor it and become more knowledgable, I may decide to move away to managing it myself. However as it stand I am very happy with what moneyfarm provides me at what i believe to be a very reasonable cost.