"obviously" to you, I guess. Not to anyone else who realizes that life expectancy beyond 30 and absence of periodic famines with mass starvation is the result of objectivity.
> whether objective knowledge is accessible at all
How to make steel, plumb our houses, cure our bacterial infections, and bring A/C power to them is not knowledge that's "accessible to all." Most of us are happy that someone somewhere knows how to do those things. That's called "division of labor."
> whether objective knowledge is accessible at all
Kind of like the missing link in the fossil record which causes creationists to say "Look! Darwin was wrong!": quantum mechanics is the difficult-to-understand problem giving an easy out to people who don't believe in science anyway. Give it a rest.
"At all" is equally fatuous, though. The philosophical problem of whether objective knowledge is attainable was settled centuries ago. "How do you really know that Einstein's Relativity is valid?" is something that was settled when its predictions were borne out. If there are still questions about it, those will be settled by more science.
It really obviously is up for debate, all the way from the fundamental question of whether objective knowledge is accessible at all, to things like the measurement problem in quantum mechanics