How to make Minecraft Java extraordinary like in the picture (Tutorial Videos)

Okay so I tried the 2048, 1024 and 512.  The 512 loads and works.   Only other mods I have installed in Optifine, and BSL shaders.  Both are for the version of the game i'm using which is 1.21.8.  Like I said 512 works but at like 2fps, it's super unplayable. Am I missing something?   I did enable POM and advanced materials like you showed in your video.  I have an Intel Ultra 9 285K, RTX 5090 and 48GB of 8,000mhz ram. Fresh install of windows.. Any help would be appreciated, I feel like I have to be missing something.

i followed the steps, but whenever i load the texture pack, it drops me down to about 5fps. I have a strong enough PC to handle it, is there anyway i can make it run in the 516x quality at my regular 60fps? Please let me know. Thanks