mamba
Legend
they are, D&D’s main competition has pretty much always been older editions. You cannot really avoid that however, short of stopping to revise the rules.However, how is WotC not competing with themselves nowadays? 3.0 to 3.5 wasn’t a huge shift (though I do believe that it was more significant than most credit it for), but then they released 4th, followed by Essentials (which was a restatement and rearrangement of 4th), with Next (not a product most saw due to only being playtest), followed by 5th, and now 5E 2024.
At least they are not publishing different editions simultaneously like Basic and Advanced D&D did, and the number of players playing any of the older versions pales in comparison to the 5e players, so at least right now they did not lose a lot of players that way.
1D&D might change that, hence the focus on it being compatible rather than the clean breaks we had in the past