The application is the job
Surface prep, the right vinyl for the curve, and someone who has done it before. Print quality is the easy half.
You can print vinyl perfectly and still end up with a bad job. Bubbles, lifted edges, a wrap that peels at the first car wash: almost all of it comes from the application, not the print.
Application is a craft. Surfaces have to be cleaned and prepared properly, the vinyl has to be the right type for the curve it is going over, and it has to be worked by someone who knows how far the material will stretch before it distorts. A van has compound curves, recessed door handles and rubber seals; a flat office wall is a completely different problem. Cast vinyl conforms to curves and stays put, calendered is cheaper and fine on flat panels: choosing wrong is what causes lifting six months later.
We do the applying. That way there is nobody to blame if it lifts, which is a useful discipline.