I can also tell you why is that:
in Salvage games are way toooo loooooong, 10k is too much, 7.5k would be better or even less.
Also: matches are rarely close, most of the time, if you loose both heavies is a guaranteed loss, since, you will most likely also loose the next relic, probably also another after that, cause enemies will heavy+super you.
Been playing it a lot lately and we were destroying opponents and ofc, those guys were frustrated and quit. You have the usual n00b, who probably doesn't even know how to quit, thus the game goes on, and the MM engine will try to find new ppl.
Thus, giving YOU the usual game in progress.
Also, ppl mostly farm it for grimoire, so they tend to quit more when they are loosing.
Tbh, if you are in a match in a bad team you will most likely keep dying for a long time, more deaths... more tendency to say ''fuck it'' and quit, hence starting the loop again.
Today i played 3 or 4 matches, all ended due to enemies quitting a loosing match. We had 3780-0 one of those games, felt bad for the poor guys.