As long as you set up SPF, DMARC, DKIM, reverse DNS, and SSL/TLS, plus do that all correctly. Oh, and make sure you pick a provider or host whose IP ranges aren't damaged goods. And don't get me started about sender reputation with the various email providers, or the often erroneous blacklists (and fighting to get your server/IPs off and kept off).
IMO, there are limitless other things I'd rather be doing than these!
You're right that all those things are needed, and it did take me a while to get them all working. But now I know about tools like mail-tester [1] that analyze your emails and tell you exactly how to fix them. Once you know what to do, it's really not that much actual work to set them up.
Sure, it all works, but it's still the old piece of shit SMTP wild wild west, because when it stops working, you can do nothing. (But usually going to the saloon, having a rough night and waiting will solve things.)
You do not need to set up DNSSEC+DANE, and, in fact, doing so is very likely to make your system less reliable; the primary function DNSSEC has in practice is to cause outages.
Observe how few of the major sites are DNSSEC-signed. In reality the only purpose signing has is allowing your site to vanish from view of the few DNS resolvers dumb enough to do DNSSEC validation.
IMO, there are limitless other things I'd rather be doing than these!