In addition to predator/omnivore, don't forget scavenger. I'm not talking "roadkill" (although that's surely part of it), but similar to brown bears (whose eating behaviors and food preferences differ from black bears). Among the first spring meals they seek out are winter kills, which are more numerous than most folks think. An example, beyond starved ungulates, are sheep, goats, and deer killed by avalanches. I remember a snow avalanche that killed a small herd of sheep on the Kenai Peninsula that attracted lots of brown bears the following spring.
As a hunter, I read a lot of ADFG Management Reports. They do pay attention and even conduct studies on predator effects on ungulates, and this has grown exponentially as the environmental movement has put political pressure on predator management. But the effect of so few sasquatches is more than minimal compared to humans (hunters, car drivers, trains, poachers, etc), bears, wolves, and lions, so sasquatch predation can easily be swallowed up by the rest of the predators.
https://www.adfg.alaska.gov/static/research/wildlife/speciesmanagementreports/pdfs/moose_2015_2025_smrp_gmu_14a.pdf
I'm sure that the dead body/skeleton thing is primarily a thing regarding their rarity. For example, there are an estimated 30K-40K cougars and an estimated 60K-80K wolves in North America. Humans? 380 million in the US and Canada. Of those millions of people in North America, some 630K are reported as missing, although we know many of them are alive and want to be missing, or are held by others. Compare all that to an estimated 5K sasquatches.
I've found skeletons in the woods. I Initially thought them as human (no skull) and called the Troopers. They turned out to be poached goat or sheep. I've found lots of moose and caribou skeletons or carcasses. Never bear or wolf...............or human.
If someone found a sasquatch skeleton, including the skull, what are they most likely to do? My bet is that they'd either call the local police (thinking they're "human"), or they'd walk away. I doubt they'd call fish and feathers, the FBI, or another agency. And if the local police investigate, what are they likely to do if they come to realize that these remains are...............funny? My bet is that they'd contact................somebody else?