All that's well and good for experienced jumpers, but tabletops are useful for people learning to jump. You don't know what you can clear until you try. It's best not to figure that out by repeatedly landing in a hole.
Answer to that is to do what kids/teens have been doing forever, bits of wood on bricks (could be a mound of earth) and launching off of it over and over. It turns into a long jump competition with marks where everyone is landing. You then make a landing ramp, no gap, then slowly make it longer, not difficult, is it?
and getting little bits of air is still fun even if you don't perfectly hit the down ramp, no need to deny that little bit of fun to everyone, and us ground dwellers don't always know if we're going to get all the way there
Which slowly erodes away other peoples hard work.
Learning skills on bikes takes hard work (physically and mentally), lots of time and acceptance that how easy or hard something is, you will inevitably fall off and hurt yourself.
Seems to me, who is a BMXer who has built trails all their life, MTB is scared of hard work when it comes to building stuff appropriate for their skill level, putting the effort in to learn something or even picking their selves up after falling off and giving it another go. There's always an excuse, whether it be time/being scared/bike/no right to be building.