Kaido is moron... He could be most influential bussinessman in OP world... Wano could be best country to live, with unemployment next to zero...
he could invest in some water cleaning and other green stuff... there should be some stupid devil fruids for that, also Queen is scientist and probably can fix such things if ordered by Kaido tbh
Every strong samurai could join Kaido for defense of wano. But they are probably idiots who would better be rulled by Kozuki clan and just gain power and money from their status rather than hard work...
Kaido realy had potention to end the world as it is in way bigger and more epic war if he just invested more in the community that works for him