Sort of depends on your reason for leaving IMO. Some people leave the Church due to sincere differences with key pieces of Church teaching or practice (the need for the Sacrament of Reconciliation, don’t accept the full-on opposition to all birth control, disgust at the mishandling of pedophile priests, etc.)
Others leave for more cynical/selfish reasons (did not like a particular priest or bishop, were not allowed to have an outdoor wedding, felt they got too much grief when they sought an annulment, etc.)
I doubt many in that latter group become productive or passionate members of any other church.
Read the article. These are committed people not the liberals you mention. Given the liberal theology fully rooted within the Roman Catholic church, the people you mention don’t have to leave.