Lewandowsky and Benzema are players who are still productive even though they are 34 years old I think they are old but they can still score more goals in LaLiga and Benzema has carved out a lot of his name, old age is no longer an obstacle for him the most important thing is a big club like Real Madrid and Barcelona still want him to keep playing at their respective clubs to be a great competitor.
You need to understand that old age never becomes an obstacle for skilled/quality players. Benzema and Lewa are experienced and skilled strikers, they know well how to score and execute every goal opportunity. That's why both players are the mainstay player or machine goals, both for Real Madrid and Barcelona. Sure, they will score more in La Liga, I am optimistic that the scorer this season should be Lewa or Benzema.