Quiz conversion breaks into four points, and a person can leave at any of them: whether they open the quiz, whether they reach the end, whether they leave their contact details, and whether that lead turns out to be useful. Looking at the overall percentage tells you nothing until you know which step is losing people.
The order of the work matters more than the changes themselves. The first screen affects the whole funnel below it; the final form only affects its tail. So you start with the headline and the offer at the entrance, then cut the questions down to four to six, and only then touch the contact form. On average a quiz converts at 15–25 % against 2–5 % for an ordinary form, though the spread by industry is wide and your own trend is the number worth watching.