You might have to spin up a bunch of servers to find one which doesn't have a blacklisted IP. Then you have to build the IP's "reputation" with the various providers before you can send a significant amount of email through it.
Good to know! I bet they have their own internal ranking system which is far more accurate than the public blacklists.
I've never had issues inboxing on gmail accounts using SPF/DKIM/DMARC + Sendgrid, even when sending 125,000+ emails (legit!) per day.
The primary limiting factor for most blacklists is not scale, but simply the fact that most of them have no more than a few data sources - most commonly spamtrap data. It's useful, but it's not a comprehensive enough data point to accurately evaluate mail.
Having dozens or hundreds of data points available - things like how many recipients open a message and spend time reading it, how quickly they seek out a message when initially opening their inbox, or a sending domain's pagerank - gives Google a considerable edge in assessing overall mail quality.
(Caveat: outbound filtering is often more difficult than inbound filtering - perhaps in part because there are fewer data points available when assessing outbound mail.)
I observed a former boss, who was very technically competent otherwise, using "mark as spam" instead of delete.
I guess if he could underestimate that button so can a million other people.
Just a few years ago, I personally experienced this sending email between two GMail accounts, and then I noticed that my (workplace!!) IP address ended up on a public blacklist within an hour. Fortunately I noticed fast enough to get it removed before any mail delivery was affected.