

A republic just means that a country doesn’t have a heritable head of state. All of those listed countries are in actual fact republics. It says next to nothing about the actual political system of a country besides the role of the head of state. Lots and lots of dictatorships are republics. Many democracies are republics as well, but as you can see it is the dictatorship/democracy part which describes the important part of those countries political systems, not republic.
Many Americans are confused about this, because they have been indoctrinated into thinking that republic is the main descriptor of their system. Mainly because it was an important descriptor back in the 18th century, when most countries were monarchies, but much less so in later times when most existing countries are republics.
You are arguing from ignorance. The terms republic and democracy and so on have rather solid definitions in political science. Republic is not a very informative descriptor of the poltical system of a country, it just means that the role of head of state in’t heritable, ie. that it isn’t a monarchy. The actual political system of a republic can be basically anything except a monarchy.