Why do celebrities only talk and open up about their struggles and lives at film promotions? #AzaadiLikhneKi

I've seen that celebrities only talk about anything when it's a promotional event for their future films, and it sounds dishonest to me as if there's nothing else you can do to promote the film. I recently read somewhere that Deepika Padukone addresses her and Ranveer Singh's 'disconnection' process following the release of Padmaavat. Just because the film is about a problematic marriage and all doesn't mean you'll make up a tale to market and promote your film. If you really want to talk about it, talk about it at events other than promotions to get the word out.