I know the solution - and the way to test it out publicly on one single event (the 10000 meters) to prove that it works!
The 10000 meters is already basically a non-event outside of major championships (and a spare few hold-out meets around the world with long histories of it being run there). I think I remember reading it might even get dropped from championships altogheter soon if some people within IAAF gets their wish. And we all know that more and more young runners skip the 10000 and just move straight to the Marathon.
So the 10000 meter track runners and their sponsors have the least to lose from a change - and the most to win by trying something new.
Here's the core of the idea:
Instead of crowning a world champ once every two years, have a 10000 world championship every two months, in six different places (on six different continents) around the world. Something like this (though obviously the order can be discussed):
February: Australia
April: South America
June: North America
August: Europe
October: Asia
December: Africa
Always 25 men and 25 women (because ”25 men/women, 25 laps” is such a great slogan).
Top 10 in every championship automatically qualifies for the next round (because that makes the race and rivalries behind that over the gold medal more interresting too; pre, per and post).
10 spots to be selected 1 each by the 10 biggest shoe companies in the world (because if they don't get onboard nothing will happen anyway - and starting line brand rivalry like that works great for PR and sponsor sales in both NASCAR, F1, Cycling and other sports).
4 spots to be selected by the organisational city/nation/region.
And the 1 final spot to somehow be voted on by fans worldwide (to enhance all the athletes' social media game and the overall fans-athletes sport promoting game against other sports).
That was the core of the idea, I've been wishing for something like that for years, I'm so glad this thread gave me the opportunity to present it here! :-)
Additional benefits: 6 championships a year works great for sumo wrestling, we already know it works in that their fans can handle that much, so this idea isn't really new in that aspect. Putting a coloured jersey on the reigning champ could be a clue taken from cycling. And after a couple of initial years the rounds to be held in Africa and Asia and South America could be used by the IAAF to let smaller nations try their hands on organizing a championship (and by small I mean really small, i.e nations that are too small to under current circumstances ever be able to host a full T&A championship or Olympics - so that part for them would be great too!).