by better, they could mean less competent in a way that a new leader who never lead a country could have some illusions-delusions about the players in the game, with different set of ideals, or someone who has less baggage, who is associated with less grudges on both sides. Or someone who has baggage, in the form of kids in the West, someone they could have leverage against.
or someone who will by the value of being new to the job will be less expirienced, bring with him in less expirienced crew of people who will leave blind spots, channels for increasing Western influence in Russia, that will allow the Wect get more leverage on Russian politics
I am not implying at all that current regime is super competent but new ones could be even less so
besides, even if its going to be someone from the INNER CIRCLE of Putin, that person will still shake everything up differently, by putting his own loyal people in the position of power and control. New president will have his own personal guard, personal cooks, personal left and right hand, personal advisors, maybe some old guard will declare loyalty to a new face, but many could go or even face...problems.
So a change in power will bring a lot of opportunity, and will be "better" for the West, by giving them many new insides, new buttons to press, new defectors, new revelations...