I know a variety of websites that operate on the level of petabytes a month that are similar to parler (4chan), or are big hosters of files that directly infringe many peoples copyright.
Parler isn't even half bad compared to some of the hosted content on the rest of the clearnet.
The reason this is possible is because of 1. Cloudflare for media content and 2. Colocation for everything else. I don't know of an instance of a T1 or T2 data center "deplatforming" any servers that weren't directly operating illigally and had to be told it was illigal by law enforcement.
Perhaps individual companies that you contract with to get that data centers internet line, sure, but again there's plenty of companies that don't care who you are and/or like parler. I know of one in New York that offers very affordable pricing.
I don’t know if that’s really true. At least not in the Bay Area, which holds the lions share of internet companies from hosting to CDN.
It’s actually remarkably hard to run any kind of website of note and not be at the mercy of some company based out of SV.