Ask HN: Advice for feeling like a failure in PhD?

I am doing a PhD in R1 public uni on Computer Engineering in the USA. PhD is something I really wanted to do because it allows me to dive deep into stuff. Turns out what I thought initially was not the whole story.

I am nearing the end of second year of my PhD. My advisor is in HPC but doesn't do hot research and I want to do efficient hardware AI research (faster kernels, ML systems etc). But whenever I read papers and see the authors and what they have accomplished and the team behind them and the prestigious schools/labs doing them while I am deep in some cuBLAS function hoping to optimize register tiling to be a nanosecond faster, I feel like a failure. I don't know what problems to work on. I wonder if what I want to do even requires a PhD.

I question if I will ever be able to do anything publishable as the labs in MIT/Stanford, their cohort of brilliant minds basically alone? There's so much out there that I don't know. The more I think I know the more stuffs keep popping up. I thought I had finally understood LLMs to their nitty gritty details but then there's even more new variants of attentions popping up. I am not sure if I will be able to read everything needed to be able to research. I want to be able to get a job in the US after my PhD(home is terrifying) and I am an international so quiting is not an option.

I am looking for any advice or if you were in a similar boat anything would be helpful. Thank you.