PNG is excellent for lossless graphics and transparency but can be large for photographs. Before optimizing heavily, ask whether JPG or WebP would suit the destination better.
What should you consider?
If PNG is required, reducing unnecessary dimensions can still save space.
Practical workflow
Start with the destination requirement, make a copy rather than overwriting an important original, and compare the output at the size where it will actually be used. If the file is still too large, consider whether resizing, compression or a different format solves the real problem.
Related tool
Tip: The smallest file is not automatically the best file. Compatibility and visible quality matter too.