Strange reasoning. Marcelo was in the first team of Real Madrid and the Brazil national team for a long time and won a lot - this means that he was the best in his position, because neither in Real Madrid nor in the Brazilian national team you can be on the field without being the best. Now he is 34 and in the last season in important matches he practically did not appear on the field and naturally he had two options - to go to a much weaker team or immediately retire. He chose the first option.
Marcelo still wants to play. I don't know if he can still perform at a high level at the age of 34, but one thing I do know is that he will not be able to show the performance they expect at this age with Real Madrid. It was also a predictable move that Marcelon's next stop would be a smaller team than Real Madrid. If they agree with Lazio on everything, it will be successful in Italy.