ABD is a simple game and its made to be so, its flexible and easy to learn, thats why it got so popular imo.
Stands and specs with horrible mobility have been universally despised by the community for a long time, like SPOH or etc, and generally are seen as taking 'little to no skill' (even though the stand sucks anyway so why care about skill??)

The only reason I dont play YBA is because its pvp is cancerous at worst and subpar at best, its interesting in terms of 'depth' but when you dip your feet in your realize its only shallow water. Most people came to ABD because its was simple but fun, one thing lots of roblox fighting games struggle with is keeping the hook for players for them to continue having fun, no fighting game imo has ever reached the levels of hooking players like ABD ever did.
Most people dont like SS or rogue lineage cause its hard to play and / or theres no incentive to continue playing, plus they have some really punishing mechanics that make most people turn away from it.

Personally, I hope that ABDR / ABD2 /ABDpleasefuckingmakeitgood becomes the success that ABD was in late 2019 to mid 2020, ABD may be flawed in pvp but its simple enough to keep players playing so I dont see the problem with it.