My game UI had three icons, each with one with a text. So in code I was adding them in what I thought was a logical way: "level" icon and text, "score" icon and text and "deaths" icon and text. This resulted in phaser using a separate draw call for each one. It's not that important on desktop but on mobile every performance gain counts. The fix was to simply arrange the code so that all the icons are added one after the other and then all the texts are added one after the other. Now there's only one draw call for all the icons and one for all the texts. This might be pretty obvious for experienced programmers but I'm sure there must be some other junior devs making the same mistake I made.