Intel Core i3 9300 's Advantages
Higher base frequency (3.7GHz vs 3.4GHz)
Lower TDP (62W vs 65W)
AMD Ryzen 3 8300G 's Advantages
Released 4 years and 9 months late
Better graphics card performance
Higher specification of memory (5200 vs 2400)
Larger memory bandwidth (83.2GB/s vs 37.5GB/s)
Newer PCIe version (4.0 vs 3.0)
More modern manufacturing process (4nm vs 14nm)