(There were exceptions, e.g. in the third world, but there was a big difference between a front-rank player (the USSR) murdering someone like Hafizullah Amin during the opening moves of an invasion, and something like the shootdown of Dag Hammarskjöld's plane during the Congo crisis: assassinating the UN Secretary General was a huge scandal at the time.)
Today, the use of weaponized CVEs by SIGINT agencies seems to have developed into a free-for-all: the big players were clueless about the potential for accidentally normalizing this practice, or the scale of the consequences as computers became ubiquitous and indispensable components of everything from hospital medicine carts to automobiles, and thereby leveled the playing field and quasi-legitimized it for non-state level actors.
And we're all going to be paying the price for at least a generation.