How good can you get at bullet chess without playing standard? I hate standard chess. Sitting there on your ass for hours on end obsessing over every single little move... it's a nerd's game. It's often talked about as being a game of intelligence, but there's a reason why computers are so much better at chess than humans, while there's no robot out there creating breakthroughs in mathematics or science. Because it's not about intelligence, it's tedious calculation and nothing else. Ultimately, all it comes down to is doing the calculations and memorizing the lines. It's a game for computers, not for humans.

It is for this exact reason that so many games end in draws. Because there's a limit to the degree that we humans can calculate and memorize lines, hence the best players are often equally good at it, hence nobody is at an advantage, hence it's a draw.

But I'm fascinated by bullet chess, or as a maximum, 3 minute blitz. Now, this is a game for humans. It's not about how nerdy you are with your calculations, it's about something that is a bit more ... intangible. It's about instinct... intuition, ... a certain feel for the flow of the game. These are human notions that you can't program into a computer, and that's what makes it so fascinating to me. I mean, a computer can play bullet too, but importantly, the computer does not think of bullet like a human does. The human plays it differently. However, in standard chess, both the human and the computer are doing the same thing: endless calculations. 

So with that in mind, my question is, how good can you get at bullet chess, without playing standard chess at all? 

For what it's worth, I am ranked 2300 on lichess (bullet), 2000 (3-min blitz) and 1800 (10-min rapid).
I think that bullet is a skill that is half chess, but half is simply the ability to think and move quickly, which is the domain of young people. Yes, you can clearly get very good at it relative to your standard level of play. Your ratings seem to prove that.

I still question whether bullet is really good for your chess on a deeper level, but you do not seem to care about that, so if you are having fun, by all means, enjoy it. Nevertheless, this may still ultimately make you plateau permanently since bullet is very shallow in terms of depth of understanding. Plateaus vary from person to person, so just how good you can get will ultimately be something that you will have to just play and find out where you stand.

If you ultimately want to improve your depth of understanding, you do not have to choose between sitting there for hours, and bullet. You can play more using controls that are more of a happy medium.