I mean....
The underlying effects of World War One are still there even without the scramble. In fact, it might even happen sooner because without the "working together"— even full-of-backstabbing, European working together— as practiced during the Scramble for Africa is not done, then coastal Africa becomes just another battleground for imperial states to build ships, conscript troops, and research weapons for or in preparation for. A World War One starting because of "some damned thing in the Congo" would be hella interesting.
So no World War One as we know it, but it is still exceedingly likely one would happen.
True... but there are a variety of factors that would change that are likely to prevent the natural tensions of commerical rivalries, the formation of alliance systems, ect. from reaching the powder-keg concentrations that result in OTL's explosions. For example, without Africa sucking up European capital (Both in terms of government expenditures in direct government of unprofitable polities and the high input costs of extracting/initial laying down of the infastructure needed to extract the raw resources), that excess capital is going to be flowing elsewhere and, not being in exclusive national domains protecting a captive market/source (One of the few advantages, alongside the military-strategic ones, that applied to African colonies at this stage) would be competing with each other far earlier than IOTL; where Empires essentially kicked the can down the road by carving the still un-closed regions of the world into economic zones more and more until there was no real "Free market" territory left. This made things like the rise of German and Russian economic potential, for example, existential crises for their rivals, since that excess potential had nowhere left to go but up against the sovereignly-protected territories and home markets of the pre-established (and having grown less efficent) industrial hegemons who now needed to be highly sensitive about maintaining every quarter of their Empire either to retain the captive market, or as strategic buffers/connections that provided access to a vital raw resource or defended/made profitable other parts of the Empire (One of the reasons Britain, for instance, ended up grabbing so many odd places in Africa)
In a world where Africa is still under the rule of local pontates with a level of economic freedom, and also not forcefully molded to act as exclusive resource extractors, you're far more likely to see a greater deal of investment flow into developing-but-still-civilized regions of the world from multiple powers at once: The late 19th/early 20th century Ottoman Empire, with its British, French, and German projects springs to mind as a template for what this might look like, or a treaty port system similar to that imposed on China. Not only would this give the rise of industrial rivalries decades to be slowly sorted through/mellowed out and flattened a little by the existance of greater inter-state competition, but as a knock-on effect would create more "mini-criseses" that are far more likely to be solved by international arbitration than breaking down into a major international war due to their individual relative non-importance, "letting off steam" in a sense between the different powers. Powers starting to climb into the industrial tier, such as the OE, Japan, Russia, and A-H, would also be tied into this system by having their newfound prosperty dependent on the incoming flow of capital from multiple rival sources, preventing them from slipping into more or less "Sugar Daddy" relationships that would turn the whole continent into a power keg. African polities, simply due to their much weaker positions and lack of desirability (in terms of profit margins) may individually fall sway to this or that company or region ("Banana Kingdoms, in essanse), but that very weakness and small size makes them acceptable temporary loses in the ever-shifting economic game rather than positions of vital importance.
For more specific situations, a lack of African colonization means that what colonial energy is still pushed is going to be directed into protecting the "2nd Wave" Asian empires which already exists from encroachment by rivals. In all likelihood, this butterflies away any attempt at Anglo-Russian reproachment and continuation of The Great Game, so Germany is never threatened by a mutual lock-in on both land and sea. French mindset also has to shift due to not being in constant-expansion mode to secure its "French India", likely retaining a more continental focus, and as the commercial tendrals of Europe reach out in search of capital markets, consumers, and resource sources are likely to draw the USA into international affairs earlier in defense of her hemisphere's position; the perfect combination of a mediator in a powerful international position with no alliances or intentions to make them to cloud her position and having well defined by limited interests outside the Americas that largely align with maintaining the status quo of "open doors". This would retard any later drift towards a neo-merchantalist stance by any of the other major powers.