Are there enough players in the old cods, if so which and which not
Yes there's! But practically only "hacker lobbies" still exist. Have fun
Don't be bullied.
Yes, in most CoD parts you can easily get a full lobby in standard modes.
And no hacker lobbies are more common than at the time the 360 was current, but are still the exception.
I can tell you that with certainty since I usually only use CoD on 360 games