I'll agree that part of the fun is clawing your way back up when something goes wrong, but pretty much everything in CK2 has some kind of reasoning to it or you can control it in some way- even something that's RNGish like health you can influence. Meanwhile practically everything in EU4 goes off dice rolls of some sort and a lot of it is very arbitrary to boot. Combat, sieges, ruler's deaths, ruler's traits and stats, rebel and native spawns, choice of advisors, AI rival choices (especially at the beginning of the game), trade goods when you colonize a province, the number of colonists received each month, and I could probably go on.
Maybe it depends on how you play the game, but I don't see how, even in your examples, EU4 is visibly more RNG than CK2...
Combat and siege... alright, maybe die rolls in EU4 are more arbitrarily random. Now, I don't like to pay close attention to the grand list of CK2 tactics, but I consider that pretty RNG too. In any case, having a bigger military force will win you the war in either case. If you have an approximately even army vs you opponent, you can have your military leader(s) die by RNG during battle and cost you the war, in both titles...
Death, traits, stats... Rulers have a lesser role than in EU4, and act more like modifiers. You can control 'death' to some extent by making them generals, abdicating etc. In CK2 rulers have a much bigger role, and their traits can affect a lot of things (especially in events... more on that later). All those events that give/take traits are also quite RNG. Send your ruler into battle and he might gain Brave... or Craven. Education has a RNG die roll too, affecting stats.
Rebel and native spawns... Well, there are no native spawns in CK2, that is true. But we have a similar % chance unrest in provinces, except EU4 moved to a progress bar while CK2 rebels can rise without warning.
Choice of advisors, AI rival choices... Well, in CK2 I'm not particularly interested in running a realm-wide breeding program, so for me advisors are pretty random too. With the added bonus that if I don't choose my powerful vassals, they get angry. CK2 'rivals' tend to be random characters and not your equals in any way...
Trade goods, the number of colonists... Pretty inconsequential things? Number of colonists especially, there are so many consecutive die rolls that the chances of deviating much from the mean are so low they might as well make it a flat number. Getting another trade good has pretty much zero impact on the course of a game, unless you are trying to always get the most advantageous die roll.
....
But that's really avoiding the core of the issue. CK2 is a game driven by RNG, especially in its many events. Try an experimental medical treatment and be miraculously cured of cancer... or be Maimed. Assassinate your liege and be one easy war away from ruling the kingdom... or be found out and counter(?)-assassinated within three months. Try to become immortal and die. (Every time so far!) (Try to imprison a plotting vassal with only 40% chance and fail: Oh No! By sheer luck my army just happened to be standing right there, but what will I do with a free revoke?!?)
Yes, sometimes in EU4 you are also dealt a hand and must then play with it. But never have I sat there for a full minute considering choices on an event window weighing the risk... unlike CK2.