My original response was to your claim that Warframe looks bad in general, which is ridiculous.
Deliver visual proof for "Warframe open world looks so especially bad" please. Would like to see your definition of "especially bad".
I would gladly capture some footage however I've already removed the game from my system.
I'll be the first to admit, in the indoor and corridor style missions it looked decent, even in the closed world environments it was OK. My main issue was just in the open world sections, when trying to see long distance everything just became a major blur. The colour palette didn't help things, it was very difficult for me to tell the enemy apart from the environment in a lot of areas.
I think open world games can look good enough on switch and my argument is not based on some type of console favortism. The switch is my favourite console this generation and I have always loved my Nintendo consoles above all others (incl. Wii U).
My own opinion is that Warframe in particular did not look that great in the open world sections when I played it and seeing as though the majority of W3 is based in the open world, is not built from the ground up for the Switch or by Nintendo, I am not extremely confident that it's going to look all that great - but am more than happy to be proven otherwise since I would like it play it again.