Hi, and welcome to the forum.
The system of pub ownership is completely different in Ireland compared to Britain, largely because the licensing system is too. The vast majority of pubs are single owner/occupier businesses. There are a handful of pub chains in the cities, where an owner/occupier has bought an additional pub, then another, then another until it becomes a chain. With GBB and The Porterhouse, where one of the pubs was a brewpub originally, they've expanded into essentially a tied estate with a separate production brewery, but they're all centrally managed, not leased out. There are examples too where someone owns a pub and its licence but leases it to an operator -- I think the Galway Bay ones work like this, so if Galway Bay decides to move out, a new tenant takes over. In those cases the owner has no involvement in the running, other than renewing the licence each year. We certainly have nothing like the UK's pubco model.