Water has reflections. Literally nothing else... because they can't change it on a per block basis. You need a resource pack for that.

Texture packs dont just magically make shaders work differently, hence you can use literally any texture pack you want including the default one and the shaders still work.

Except they do. Why talk like this if you genuinely don't know what you're talking about? You NEED a resource pack to enable

• Normal maps (smoothing)
• Parallax maps (bumpiness)
• Specular maps (shininess)
• Reflections on a per-block basis

Without a resource pack, all you have is fancy lighting and fancy water. That's all it CAN do because it doesn't have any of the information it needs to use any of the other effects. The standard and most custom texture packs don't include it.