I was half expecting the fighters to form vehicle Voltron myself lol

All six Stones were needed to erase half the universe: each played a part in the process, it couldn’t have been done if even one of the Stones was missing. The roles played by the stones:

Did you miss when Onyx shot them both straight through the head? I doubt they’re coming back.

It’s not a character death on The Flash. They’re finally having a mass funeral for everyone’s common sense.