I understand your desire to want Anointed mobs to be a balanced and satisfying challenge. But again, that is a completely separate issue from Mayhem modes and their modifiers.
It’s akin to fishing. You don’t want the fish to be too small, quick and easy to catch, because then there won’t be any sense of achievement in catching them. You also don’t want them to be freakishly huge and too difficult to catch, where they snap your line or eat your boat (with you in it), because then it would be too frustrating and pointless, not to mention dangerous. You want the fish to be of sufficient size and challenge to make the endeavor both fun and satisfying.
Mayhem modifiers in this analogy affect the fish and everything around it. They randomly dictate the weather, the state of the water, the type of fishing pole you use, the test of the line, the lure, the size of the fish, and so on. In each random variable, you can simply work around it. If the weather is cold, you either dress more warmly or you utilize a shack (ice fishing). If the water is too murky, you use sonar to make it easier to find the fish. If the fishing pole is too short or too thin, you use a longer, thicker one, or vice versa. If the test of the line is too low, you use a higher test, or vice versa. If the lure isn’t working, you use live bait. If the fish are too big, you can use a bow or a spear (bow/spear fishing is actually pretty easy once you understand refraction). These varying conditions don’t make catching the fish more difficult, they are merely different conditions that you must work around to achieve the same result - catching fish. And if you don’t like those conditions, you simply come back a different day when those conditions are more favorable, not unlike resetting the map to get different Mayhem modifiers.
Mayhem modifiers only randomize the conditions under which we play. They require no skill to navigate or negotiate, and therefore add no actual difficulty to the game. In our analogy, if we wanted to make the fish more difficult to catch, they would be smarter, faster, stronger. The increased difficulty wouldn’t be something you can avoid or ignore. Or like they do in some fishing contests, you have to catch as many as you can within a time limit. There is no working around that - you still have to perform the process of catching them, but more quickly and efficiently.
The point is, they are two separate and distinct problems in this game. The issues with Anointed mobs are completely separate from the issues with Mayhem modes. And while I agree with your premise that the game becomes boring if it’s too easy, Mayhem modes don’t actually contribute anything to that - it is a pointless, frustrating, RNG mechanic attempting to disguise itself as a difficulty slider - yet easily avoided, mitigated, or ignored. True difficulty would be something that is consistent, reliable, and unavoidable.
For instance, adding armor to shielded mobs that don’t normally have it in TVHM, or adding a second health bar to mobs that are already armored in TVHM, or spawning more Badass mobs in place of regular mobs in TVHM. In UVHM, these values would commensurately scale, and only Badasses (and Anointed) would spawn. These are just some examples that other players have suggested elsewhere on these forums, but the common denominator among all of them is that it is consistent, reliable, and it isn’t something you can avoid, or mitigate, or ignore. It adds difficulty because they are tougher and therefore take longer to kill, which when combined with mob density, can be fatal if you’re not playing smarter and/or optimizing your build and gear. Linear progression, which is what we have in this game, should be accompanied by linear difficulty scaling. That’s a far more effectual mechanic (and why it’s used across nearly every game out there that incorporates linear progression) than the RNG variables of Mayhem modes.
Anyway, as I said before, this whole tangent is off topic, and I don’t think it’s fair to continue it here. If you’d like to respond further, I recommend continuing the discussion in the topic that is dedicated to Mayhem modes here. As for me, there’s not much else I can contribute here, so I will refrain from further comment.