Propulsive landing is really hard, see the failure montage from Spacex as they iteratively worked on it. SpaceX also had a very strong incentive to develop the tech, since they are a commercial launch provider and could make more money. All the engineering was certainly not free, and the vehicle has to make some compromises in terms of lift capacity and such to make it work. Propulsive landing only looks easy now, but it is a supreme feat of engineering.