>Learn all about and generate SPF, DKIM, and DMARC records but still regularly get sent to the spam folder or IP blacklists if your recipient has a big-provider email?

This is my biggest complaint when self hosting. You do everything right and they still send your mail to junk or just silently discard it while telling you 250-Ok for "reasons".

Microsoft have already recently kicked out self hosters from their "Smart Network Data Services" portal by only allowing the ASN owner (ie. your cloud provider) to access it.