You can't, because despite ladder usage weirdness, it's a set that exists and has to be respected. You also just ignored the part where it needs Z to even break the loop, which btw Wellspring can simply pivot out of to bait and waste your Z and then Bolt is REALLY stuck.
No one is switching lele directly into it unless they have no other options. Which is only happening if: the lele player somehow doesn't have other soft checks (which there are many of), or somehow let themself get put in that position. Your whole "well it can just tera" is weak considering Bolt isn't gonna auto tera in that instance, especially when the Bolt user has to account for the rest of Lele's team. It's much more nuanced than you're trying to reduce it to because you wanna make Bolt seem broken.
You didn't refute or defeat. Also drop the attitude it's not helping your argument at all.
Sun Raging is not that common because it's a very high maintanence playstyle (it's good, but you're running ZardY and at least two forms of anti hazard tech to ensure Zard can keep coming in). You're also taking ladder usage a little too honestly considering Wellspring is the type of pokemon that has such a free 4th moveslot, it can and will viably run anything (SD/Ivy/PowerWhip/4th move) and thus all are possibilities to be respected. You keep calcing like Proto boost is the most common example, but if the opposing Bolt is Booster then all it takes is it being chased out once (not hard to do) and Wellspring cleans it with boosted PR (and Bolt becomes easier to manage anyways).
Lele is almost always choiced and clicking any move besides FB meant it was losing most, if not all health to pursuit on the way out. Gholdengo only sometimes ran Z fighting because of Gambit, but it was still less common because lefties NP and covert cloak NP were much better back then.
It's not cherrypicking really. ZardY frequently runs Scorching Sands which heavily damages Bolt if it comes in on it, while Wellspring as mentioned can both beat it with +2 PR (or hell, after just one switch in to unboosted Ivy Cudgel and Bolt drops to +2 Superpower too). It checks them, but is not at all a hard answer to either. As for your claim that Bolt is ran on sun as much as booster energy off sun?
Yeah no.
As for Kingambit, it was a fantastic buffer for a ton of teams against a huge amount of frail offense teams and cheesy HO. It compressed this as well as the other utility I mentioned in one single slot, easing building. Of course we still banned it because despite this, it itself was highly difficult to handle because of its power, but it was a more impactful defensive piece than Bolt ever could be. Kingambit's entire role was not endgame sweeper, it was excellent throughout games because of pursuit and knock off.
"i dont really care about the immunity because all the pokemon that are immune get terad" it's not nearly as straightforward as that. You're basically sticking your fingers in your ears when you make comments like this. Also your Valiant example is silly because Valiant commonly runs encore, can run Destiny Bond and will realistically be able to lock down Bolt in most scenarios so the team isn't overwhelmed by it one way or another.
Yeah you can just quit right there. I played during the Kingambit meta, and got reqs to ban it. Dark was a common type, but it was not the only type it could run. It's one of the most tera flexible pokemon in the game. Kingambit cripples fighting types switching in with knock off. That's quite literally what that means. Also "its also not doing shit with sucker punch unless it has enough fallen teammatesz" says you either didn't play the meta or didn't play enough. Even early game Gambit had immense strength to pressure frail offense without boosting (and that's if it wasn't running Blackglasses, which made it even more devilish.
The rest of this is just "Bolt being in the perfect conditions every scenario therefore it can't lose" which is both unrealistic and not common. Bolt on Sun is the LEAST common way it's used, so using every calc as if it's on sun and CM is very disingenuous. Though one I want to specifically touch on because it tanks your post more than anything,
+1 252+ SpA Protosynthesis Raging Bolt Draco Meteor vs. 252 HP / 252+ SpD Vessel of Ruin Ting-Lu: 295-348 (57.3 - 67.7%) -- guaranteed 2HKO after Leftovers recovery not to mention the z move
FayaWizard already corrected you on this calc being wrong but for some reason you repeated it.
+1 252+ SpA Protosynthesis Raging Bolt Draco Meteor over 2 turns vs. 252 HP / 252+ SpD Vessel of Ruin Ting-Lu: 397-468 (77.2 - 91%) -- not a KO
In short, you need to consider what is most commonly used with Raging Bolt which is either Booster Energy or Z. Sun is viable but not common due to the high maintenance it requires, plus the ban of Walking Wake hit them pretty hard as that was the team's main anti offense tool. So, Booster sets are manageable because it's not hard to force a Bolt out and lose the boost, while Z sets lack as much instant power and thus are very manageable with good building and play. Even sun is very possible to manage by simply putting pressure on the sun team with offense, while slower teams have it tougher, can still limit it with hazards, status and chip.