The centre-back made 34 appearances in all competitions last season, but the arrival of Marquinhos from Roma meant that he was likely to fall down the pecking order at the Parc des Princes behind the Brazilian and his fellow countrymen Thiago Silva and Alex.
It would have also put his chance of a recall to the France senior squad in jeopardy, but having been selected for the upcoming World Cup qualifier against Finland and a friendly with Australia, Sakho believes that his decision to move to Anfield has been vindicated.
"I had to quit Paris to get back in the France squad," he told French newspaper Le Parisien. "Being picked again proves many things. That I still have that level. Most of all that I didn't leave to join a big club because of the competition [at PSG].
"At Liverpool there are also very good players in my position, but the competition is clean. At Paris it had become complicated. I've put that behind me and closed the door. The day I decided to leave PSG, I just got on with it."
Sakho has made 14 appearances for Les Bleus.