For DOS, IMO, it's overkill. DOSBox-X does a very good job even for late and heavy dos games and is far more performant. A big advantage of DOSBox is not needing to setup a real OS inside the emulator - things just work.

For Windows things are the opposite, however. 86Box's better emulation of real hardware makes it far easier to setup the drivers and in general make the OS work well (on dosbox there are quite some quirks last time I checked, essentially requiring you to follow a specific guide, tweak some settings etc; on 86box it's just good old "install the os, put on the drivers and you're good to go"). Also, I notice that 86Box vms tend to be considerably faster than real hardware of the same level (likely will not be important for most games).