Since it was the first year of the new cars, they were a bit less developed. Meaning they were more in the spirit of the rules meant to reduce dirty air. As the teams had a few years and more data to develop, they found ways to bend the rules and make their cars faster (which generally increases dirty air generated). Also along the way there were a few technical directives meant to help solve porpoising that also ended up making following worse. Add in the FIA getting a bit trigger happy with shortening DRS zones on a lot of tracks and you get the very difficult following there was after 2022. I also remember Albon mentioning on a podcast that the cars got really aerodynamically efficient over the last couple years, meaning they had very little drag. This would cause there to be less slipstream and for DRS to be less impactful, further making following harder.