Always felt comfortable with 2.5nm spacing at LGW, and landing clearances as the departing is rotating, because, it is "planned" that way, and IF it goes wrong, they have a game plan.
Problem with BCN is that stuff like that happens by default, and the plan is. . . . . . . . well, there is no plan.
Unfortunate consequence of course, as said already, RW crossings will go out of fashion. Oh well, good for the block hrs.