“Should I switch to LD-2020?” Older models, latest versions, and (un)critical upgrades

How old is liberal democracy? According to Fareed Zakaria, who pointed to 1945 as its year of birth, it is 75. Though precise, Zakaria’s claim only makes sense in the context of his increasingly dubious distinction between democracies that are ‘liberal’ and those that are ‘illiberal’. If Zakaria is wrong, and if liberal democracy is not 75—then how old is this model of government? Could it be that liberal democracy expired long time ago? Or is it simply getting increasingly difficult to keep up with its ever more complicated versions, whose distinctive characteristics keep ‘morphing’ and ‘shape-shifting’? If so, which models of liberal democracy still count as sufficiently ‘liberal’ and ‘democratic’? Who’s to tell? Those who wish continue using their allegedly outdated models of liberal democracy without having to download the latest batch of allegedly critical upgrades? Or those who push them to replace their deliberately degraded models with the latest version of liberal democracy?