The idea that underprivileged groups create echo chambers is laughable when you think of the number of explicity conservative social media platforms.
As I said to someone below, my guess is that you are not part of an oppressed group? It is very easy for those used to privilege to criticise those from less privileged groups for wanting their own spaces because they have not experienced what it is like to be othered.
The point is to be free from the oppression that they experience often on a daily basis, not to keep their ideas unchallenged.
This has been going on for years, including inside the EU, for those wondering. You can test to see if it happens for you by going to a flight website, getting a price for a flight, then go back a few times to search for the same flight.
The question of what you do to fight it is by clearing the cookie for the website, using a different browser and/or changing your location/block tracking (use a VPN or tor). Usually clearing the cookie is enough.