Difference between difficulties

What is the difference in the difficulties in the sections between SAT and ACT?

new SAT and ACT are now very similar.
Writing sections are almost the same now, reading for both is fairly similar, I believe the new SAT math is now more similar to the ACT math as well… obviously the SAT doesn’t have a science section, which the ACT does have.

the ACT has more prep materials as of now than the new SAT, so perhaps use that to make your decision.

(Essays are quite different)