Crunched textures on iOS

I read a lot of post and forums that PVRTC is only option on iOS. e.g. https://forum.unity3d.com/threads/unity-is-not-a-serious-2d-game-dev-platform-without-support-for-lossless-texture-compression.309171/

Is it still true that I can't have png images that I will load in RGBA natively?

I understand that I can put PNG in Resource folder or even web. Load in memory decompress in RGBA texture. But I will not see see it in sprites in Editor. it is one reason why I use unity.

is there no option to compress RGBA texture when stored on disk? even with Unity 5.5 ??? PNG, JPEG, GZ, LZMA, where ever.