Is Phillip income ETF a better choice than buying STI index from DBS considering the management fees at Phillips?

What is your investment objective?
The investment objective of the said Phillip ETF and the STI ETF is quite different. Phillip, as the name implies, is for income and STI ETF is for broad market exposure with no style biases.

Hi, if I were to attempt to choose an ETF for purchase. Management fees would not be my sole factor:

Just a brief look into their indicative holdings (The companies these ETFs have invested) and they both have a different portfolio when it comes to their investment.

Phillip Income ETF

Nikko AM STI ETF (The one you buy from DBS)

There are many factors in play with regards to an investment, I would recommend you do your own due diligence before making the choice.