[Kototama]

One problem with encapsulation is that it is used to protect modification of the internal state of an object against external modifications but with very little benefits. Languages which are more relaxed on this subject (Python in some extend, for example) have shown that programmers are, most of the time, just not stupid enough to mess with the internals of an objects and that all the ceremony of encapsulation brings little value.

In top of that, a much bigger problem is that encapsulation is fundamentally broken, it does not prevent against what a real source of bugs: concurrent accesses on the object.

[zozbot234]

The point of encapsulation is (1) to protect meaningful invariants of the internal state - you care about external modifications because those might break your invariants; (2) to abstract away an object's interface from how the internal state happens to be implemented. Sometimes there are meaningful choices to be had in implementation, and any allowance for "external" modifications basically adds to your object's interface and breaks that abstraction. Both of these can be useful. Concurrent access is yet another issue, of course, and newer languages make it easier to control it.