The DJI Care refresh for Mavic pro costs 119 euros. Under this plan, first time replacement is 99 euros and second time replacement is 139 euros. What is the point with this complicated approach? Why not just say that all new mavic drones come with two possible replacements at 158 euros and 198 euros in the first year?

Because there will be lots of people who pay the 119 euros and don't claim this will offset the ones that do claim.