The Crucial T500 1TB wins in 3 out of 7 comparable specs, with 2 ties. Its biggest advantage is MSRP (76% better).
WD Black SN850X 4TB wins in 2 specs (Capacity: 300% better).
Recommendation
Choose T500 1TB if you want the best overall performance — especially msrp.
Choose WD Black SN850X 4TB if capacity matters more to you.