When did the Irish commit a genocide? When did the Irish invade and pillage other nations? When did the Irish ethnically cleanse a land claiming that god gave it to them? Your problem is that you reduce the world to Western Europe, and history to the last 500 years, and even then, I found Ireland as a counter example in a continent with a history of colonialism, genocide and ethnic cleansing. Everyone was doing it, is not an argument, and is not true.

If we move out of Europe we find even more examples of nations that don't have a history of genocide and colonialism. Take Egypt or Iran or Chad or Algeria or Vietnam for example. In fact, any country that was a victim of European genocides and colonialism by definition is a counter example. Namibia therefore is another example.

The countries founded on settler-colonialism and ethnic cleansing are a minority, and mostly exist in the new world (USA, Canada, Australia, New Zealand, Argentina) except for South Africa before its liberation and for now Israel. Very few countries in all of human history has been founded by replacing the indigenous peoples by foreign invaders. The empires of the past such as the Roman Empire focused more on assimilating the indigenous peoples not replacing them. The Crusader Kingdoms is a historic example of European settler-colonialism and we know how that ended, it was nothing like Roman or Byzantine rule of the Middle East. French Algeria is another more recent example. Everyone does it, is really just your way of saying a lot of European empires did it, and everyone else isn't human or doesn't matter.