Thinking about deliverability

I was chatting with folks over on one of the email slack channels today. The discussion was about an ESP not wanting to implement a particular change as it would hurt deliverability. It led me down a path of thinking about how we think of deliverability and how that informs how we approach email.
The biggest problem I see is the black and white thinking.
There’s an underlying belief in the deliverability, receiving, and filtering communities  that the only way to affect sending behavior is to block (or threaten to block) mail.

This was true back in the ancient times (the late 90’s). We didn’t have sophisticated tools and fast CPUs. There weren’t a lot of ways to handle bad mail other than to block. Now the landscape is different. We have many more tools and the computing capacity to quickly sort large streams of data.
At most places these days, blocking is an escalation, not a warning shot. Many places rate limit and bulk folder questionable mail as a first strike against problem mail. Sometimes the mail is bad enough to result in a block. Other times, it’s not bad enough to block, so it disappears into the bulk folder.
There’s a corresponding belief in the sending community that if their behavior doesn’t result in blocking then they’re acting acceptably. This isn’t true either. There are a lot of things you can do (or not do) that don’t help delivery, but will actively harm delivery. Likewise, there are things you can do that don’t actively harm delivery, but will help. All of these things add up to reaching the inbox.

It’s all shades of grey

Things don’t happen on a short timeline. Bad email behavior might take days, weeks or even months to affect things.
Take the situation where a company buys a list and starts sending spam. On one side we have anti-spammers on the other we have marketers.
Anti-spammers often react to the spam to a purchased list with bluster and threats. This behavior is illegal! It’s against CAN SPAM! All your mail will be blocked! Your ESP will throw you off! Yeah, no. That’s not how it works back here in the real world. Purchasing lists is not illegal under CAN SPAM. Blocking might happen, but unless it’s a filthy list it’s not likely to happen the first time. Many ESPs will work with senders, requiring them to remove the purchased list but allowing them to continue mailing their regular lists. Eventually, people start ignoring the boy who cried spam.
It’s not like senders are all honest about the effects of purchased lists, either. Talk to a few marketers and they will swear blind purchased lists are great. They’re kinda right, in the short term under very specific conditions. If the sender starts out with a good reputation, makes smart purchases, and pays attention they’ll often get away with purchasing lists for a while. Eventually, though, delivery problems show up. But because the problems take so long to show up, they refuse to believe purchasing lists led to their mail going to bulk.
In both cases we have folks who aren’t looking at the whole picture. Thus, you end up with delivery folks who simplify their message to “it will hurt deliverability” when the reality is a lot more complex. Sometimes senders have a bad ideas that shouldn’t be done, even though they won’t hurt deliverability. But they won’t listen to any advice containing more realistic consequences.