head to head
WWE 2K20 asks more than Wii Sports, and the gap is reads.

Execution · Pure Mechanics
Motion-controlled tennis, bowling, golf, baseball and boxing built around simple swing gestures.

Execution · Competitive PvP
Reversal timing and grapple guessing games in a famously buggy wrestling package.
Wii Sports leans Execution (Pure Mechanics); WWE 2K20 leans Execution (Competitive PvP).
Wii Sports leans a little harder on execution, though the gap is small.
Wii Sports
Motion swing timing and accuracy decide every event
WWE 2K20
Reversal timing windows decide matches but inputs stay forgiving
WWE 2K20 leans clearly harder on reads.
Wii Sports
Casual local opponents add light mind games
WWE 2K20
Human opponents bait reversals and mix grapple choices
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Wii Sports
Minor physics wobble and CPU behaviour randomness
WWE 2K20
Notorious bugs add chaos; systems otherwise deterministic
WWE 2K20 leans a little harder on optimization, though the gap is small.
Wii Sports
Simple technique tricks like bowling spin are learnable
WWE 2K20
Move-set knowledge and stamina management give an edge
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.