Comment by ASalazarMX

I hope I get to see the next thing after browser applications in my lifetime. I fully understand the advantages, but it has grown so fast and so wild I think it has to eventually fall down by its own weight and complexity despite its immense success.

It's not that the presentation layer need conditionals, it's that the layers under it have grown full of hacks that need more hacks to work around them, because the web was designed to grow documents, not programs.

If the web had been designed for applications in the first place, the presentation layer probably wouldn't need conditionals at all.