Sildurs Enhanced Default Shaders 1.19 / 1.20.+(No Lag)

Sildurs Enhanced Vanilla is a very optimized shaders that can work on nearly all devices, it looks so good in spite of it being a vanilla shaders and only changes a few assets, I really enjoyed playing it on survival it doesn't interfere with vanilla Minecraft and always keeps you on a constant high frame rate. Another cool feature about this shader pack is that despite being vanilla-ish shaders it's still compatible with some realistic features like PBR and POM, so you will be able to play it alongside a realistic texture with no issues at all.

the shaders are completely free and there are other versions ranging from lite all the way to extreme, choose depends on your gear,  I honestly felt comfortable with this one but it's entirely up to you to decide.