Qualcomm Snapdragon 855 Advantages
Lower TDP (6W vs 10W)
Qualcomm Snapdragon 888 Advantages
Better graphics card performance FLOPS (1.72 TFLOPS vs 0.8985 TFLOPS )
Larger memory bandwidth (51.2GB/s vs 34.13GB/s)
More modern manufacturing process (5nm vs 7nm)
Released 2 years late