Semantics make hard assertions about "containers" worthless. It depends on what one means by a container exactly, since Linux has no such concept and our ecosystem doesn't have a strict definition.
It is the most widely used sandbox layer for pretty much everything. What escapes are you talking about? Are we supposed to take your word for it? Come on
Wait. What? What escapes? Is it that bubblewrap not faithfully implement the policy you give it or that there are surprising gaps in the kernel's namespace isolation?