“return” is simply optional in a void function. Many use it as, IMHO, it is old programming habit that every function must return something. In prior programming days, there used to be functions and subroutines.
Functions were really subroutines that returned some sort of value, subroutines simply did some processing that was going to be repeated at other times in the main line of execution. Subroutines never returned anything, but modified something (internal variables or screen, etc.).
In C (and thus C++), gone were the concept of subroutines - everything became a function. Functions always return something. C allowed for subroutines by specifying the return type of “void.” It has been a while since I’ve done C, so I can’t recall directly if return was required, but I do believe it was - every function had to “return” back to the main execution.
Now, however, “return” is optional for a function that returns “void.”
Hopefully I have the history correct - has been a while.