Reddit didn't turn into an echo chamber due to time and algorithm. It became one as a result of company policy and censorship. For much of reddit's history, every form of viewpoint, opinions and speech were allowed. Everything changed once Trump got elected and the company reached for the ban hammer and decided to take sides on all cultural/political issues. Now, it's a ridiculously botted political propaganda outlet for the establishment. The 2012 reddit is unrecognizable compared to 2022 reddit.