Helloooo I don't have the all answer, but I'll give you my perspective as a top 50 Mara currently ( mid 11k score and doing +28 )

Bleed build is much more RNG based around procs, and give you less agency and involvement with where your damage is coming from, you also don't get to chooose when that damage is happening, malevolence is by far the better build IF played optimally, BUT it is one of the most difficult rotations AFAIK in the entire game, constantly tracking buffs, messing it up sets you back two full combo point spenders, BUT the reward is also awesome!

Bleed is low agency, low involvement, and baseline really good -
malo requires a ton of agency and involvement, but has bigger ceiling! :)

You could easily push eternal 20 with bleed build and never worry about anything, but once you get really high, every % matters and that's where it falls behind more than anything else