The same applies to the shaft: same sports family, different requirements.
Tennis is often about long, explosive straight sprints - advancing to the net, chasing a lob, running for a stop ball. Tennis shoes are therefore optimized for forward stability. A stiff forefoot and well-fitting lacing prevent the foot from jerking when pushing off.
Long straights are rare in padel. The court is smaller, the boards limit the space, and many points end at the net through volleys. Typical are short, explosive sideways movements, lightning-fast turns and chasing balls that bounce off the glass wall. The Padel shoe shaft must therefore primarily stabilize laterally: the foot is constantly tilted to the left and right in order to initiate rotational movements - without the ankle giving way.
Conclusion shaft: Padel shoes protect the sides. Tennis shoes protect the front. For padel, lateral stability is more important.