If you manage to get an apprenticeship at a good company like Siemens, you'll receive great education. They put a lot of effort into educating apprentices, and after three years you'll be able to get a reasonably well paid job quickly, either at the same company or at a different company.
But especially lots of smaller businesses don't have the time and resources to take proper care of their apprentices. Especially in the service industry, apprentices are just hired because they provide cheap labor. Apprentices at restaurants or supermarkets will often spend three years performing only the most menial work, and the "Berufschulen" (vocational schools) are extremely low quality. After spending 3 years in an apprenticeship like this, you'll have trouble finding a proper job, since employers would rather just hire a new cheap apprentice.