When would you advise someone to switch from one Robo advisor to another? Returns from one to another are so different for the same time period!

Personally, I made the switch from SA to AW. There are 3 main reasons for the changes. Firstly, fees charged by AW are much lower and that would erode less into my returns over the long term. Secondly, investments are held in my name with SAXO, a custodian, instead of being co-mingled with everyone else. This gives me peace of mind that in the event the platform closes, I will still be able to retain my holdings. And lastly, the complexity of AW portfolio is much lesser than SA. It's easy to understand and works well.