Your image: 4032x3024 (12.2 MP)
6x4Good quality
8x6Good quality
10x8Good quality
12x8Good quality
16x12Too low
A4Good quality
A3Too low
300 DPI is the standard for quality prints. iPhone 15: 48MP (8064x6048). iPhone 12: 12MP (4032x3024). Most phones are fine up to A4.