I had an excellent Braun Sixtant SM31 from my father. It always cut sharply until the foil was worn through. Replaced the foil and two years of peace and quiet. With the new appliances, wear and tear seems to be priced into the "product quality". The "predetermined breaking points" are now built into almost all products somewhere.

To your question. Yes, after 10-12 months (depending on hair growth) the shaving head is blunt and has to be replaced because it no longer cuts properly. That's what we call "progress".