Even if you have a PhD it isn't necessarily easily to find a job as a lecturer in an university. Often the criteria for hiring a lecturer is their publication record, and if you leave academia for the industry you probably won't be writing any papers. Without publications getting a lecturer position probably won't happen. This is the case in most European universities that I know. Also, the average time a student takes to complete a PhD, especially if you are planning to work while you do it, is well over 5 years.