The Western Digital WD Black SN850X 1TB wins in 3 out of 7 comparable specs, with 3 ties. Its biggest advantage is MSRP (20% better).
Rocket 4 Plus 1TB wins in 1 spec (Endurance (TBW): 17% better).
Recommendation
Choose WD Black SN850X 1TB if you want the best overall performance — especially msrp.
Choose Rocket 4 Plus 1TB if endurance (tbw) matters more to you.
