Gen 9 performs in general better because Intel was once in mobile and it became optimized for this. I even saw Cherry Trail doing better than some Iris parts.
Also, if you look Anand's Galaxy S10 and iPad Pro 2018 review, you'll see that the GPUs throttle to about 2/3rds the performance or less.
GPUs that outperform HD 620 at peak, underperform it when running the bench sustained. Even the iPad drops to 60% of the performance when running
Yes this is such a nonsense, nervertheless some people like to compare Android phones with bigger windows devices. Also we can be sure phone vendors have gfxbench optimized like hell. Intel could probably do the same with Gen11 in future driver because they did quite well @Gen9 with almost 1/3 the raw power. It's even worse for AMD with mobile Vega.
And then ALU 2 is purely synthetic and most likely the worst benchmark when comparing architectures.
It gives you a better picture about the GPU capability than the synthetic 3d benches.