That is much, much too simplistic an answer. You’ve also confused “gradualistic processes” with mainstream geology. Mainstream geology posits a combination of both gradualistic and catastrophic processes of varying degrees of scope and magnitude.
It is not at all clear why we would not expect that, and surely any expectation of what we should find would depend on local circumstances. Even now in the present, the environments and processes occurring across the globe are far from identical in scale or type. There are no glaciers anywhere near where I live, just to pick an example.
So what? Mainstream geology doesn’t say there were never any catastrophic burials taking place. Big but ultimately local and restricted landslides happen.
I’m amazed at this extremely simplistic thinking you’re exhibiting.