In many cases, yes, public fields are fine. But there are limitations:
- Can't synchronize access. `synchronized` keyword is not applicable to fields, only to methods and code blocks.
- Can't proxy. Not possible in public fields, therefore can't intercept calls before state is changed. This is useful for example in mocking frameworks, and telemetry libraries.
- Can't evolve. Methods allow encapsulation, which allows evolution of the implementation detail. For code base where the public field is accessible by consumers only within the same code base, this may be fine. But for shared libraries, it can easily become a problem.