I am seriously have an issue understand what you think on this. If I said went to see a SF movie and it was so boring would ask me well if you find this one SF movie why would go see another movie.
My point of view is that, if the system is delivering results that bore you out of your mind, the easiest thing to do is to change the system. With your example about the two natural 20s in a row, what if the DM said, "Ugh, this guy has something that will block that damage, but that's lame. How about we put in a house rule that, if the PCs roll two natural 20s in a row, you deal HP damage like normal but you get some other special effect - like blinding or otherwise maiming the target. In this case, how about this: your arrow knocks loose the brooch the dark elf is wearing and the arrow sinks deep into its flesh."
When we play 3E we have an unwritten house rule about initiative - if the stop-motion turn order makes no sense, you can take your actions simultaneously. e.g. If you're jousting you don't have one guy move half-way down the list and wait there for the other guy to charge at him and get an attack (or have one guy charge all the way down and hit the guy while he stands there, unmoving); you both take your turns at the same time and meet in the middle. We did this because we didn't like the results that the system was generating.
98% of the time the game is fun it why I have been playing for +30 years.
That was the sort of response I was looking for - the game is almost always fun, so there's really no need to change it.
The reason why I suggest changing the system instead of fudging on the fly was covered in a previous post:
I believe that it has to do with player agency. As a player you make choices about what to do in the game based on how the mechanics work. Changing HP based on meta-game considerations means that it's difficult for the players to make concrete choices, because those meta-game facts are not as clear to the players as the mechanics written down in ink. If they are that clear, then that's something else (welcome to game design!).
Being bored would be one of those meta-game considerations. The DM would have to determine how many players are bored and how much and if it's worth fudging to fix that, which I don't think are easy decisions to make along with everything else a DM is dealing with; and you also create a perverse incentive: "When we're bored the DM ends fights quickly, so if I want a fight to end quickly I should look bored." As a player you don't know if you're going to have to use a limited resource (cast a spell, drink a potion, use a charge of a magic item) or if you should hang on to it because Alice and Bob are making dice towers and doodling.