Pin Oak Leaves are the worst I have seen for blocking gutters.

The way they traditionally attach down spouts to gutters is bad practice.
It causes blockages.

At the end of a gutter run,
a long radius ninety degree elbow should smoothly turn the whole gutter width downward,
that would not block up with leaves, twigs, etc.

In mineral processing plants where both rocks and water are flowing in pipes and chutes,
you learn the hard way not to create a gutter-like downspout connection,
it will jam frequently and wear out fast.

Someone should market a blockage resistant end of gutter turn down,
not the leaf filter gutter roofs,
or the “radius slot” tops that catch water but partially allow leaves to fall below the gutter where they eventually must be raked up.