> The main argument seems to be that because we're not having forced arguments and considerations in meatspace, mano-a-mano, we're not challenged enough.

In meatspace social pressure exists unlike on the internet. An example is racist/misogynist jokes are not acceptable in most IRL contexts (especially those that are being logged/recorded permanently as is the case on the majority of the modern web) whereas on the internet it's not only discouraged but it's actually a great way to build a following quickly.

The internet is fundamentally changing how we communicate, ingest news, and share information.

The argument is that before safe spaces and echo chambers online, individuals that aim to engage general public with their message in any meaningful context are forced to compromise their extreme views. In my view Alex Jones wouldn't be a nationally recognized name before the internet, at best he'd be able to get influence over 30 or so of his local conspiracy theorists. No publication would print his views, because of how large a portion of the population they would alienate and anger. I'd argue this pressure is a net positive and having it removed online is leading us down a dark path.