Optifine is available for the 1.16.5 version of Minecraft Java. All the screenshots that you can see on my blog use optifine and shaders. Optifine help you optimize Minecraft but also allows you to use shaders and it gives to Minecraft a much better look, i really recommend it to you !
Shaders in Optifine
In june, i did a post about my top 3 shaders for 1.15.2. I still use those 3 and this post is still a good reference if you want to start enjoying Minecraft with some of the best shaders available. Just to give you a few examples, here are 2 screenshots of the “almost ready” Waterlands free server, without and with shaders. I use the last BSL version mainly. Enjoy !