Bedrock combat is better than Java - and that fact (Bedrock was released after Java 1.9, and never got the same crap combat overhaul) proves Mojang knows Java combat is not ideal, yet they have not brought Bedrock combat over.
Instead, in the past, all we got were "Combat snapshots" that were completely separate from the regular snapshots, and that drastically altered other aspects like saturation, instead of the K.I.S.S option of bringing over Bedrock combat.
Oh, and since that combat overhaul takes the form of an attribute ("attackSpeed"), it cannot be easily altered; the only way is to use custom commands to /give players a piece of equipment with the attackSpeed attribute modifier set to a very high number. It's not something easily changed like a World Option or /gamerule or anything, which makes it even worse.
That's my biggest pet peeve with Java Minecraft (Bedrock? Get rid of the goddamn store!).