MediaTek Helio G91 Advantages
Released 3 years and 1 months late
MediaTek Dimensity 900 Advantages
Better graphics card performance FLOPS (0.621 TFLOPS vs 0.096 TFLOPS )
Larger memory bandwidth (18.4GB/s vs 13.41GB/s)
Higher Frequency (2400MHz vs 2000MHz)
More modern manufacturing process (6nm vs 12nm)