I know I've said this before here but.. it goes the other way too.
People make a big deal of SPF/DKIM etc. I think you should, for the sake of best practice. But you can set yourself up with gsuite or Office 365 and pay no attention to these things, and you can fully expect mail to get through to everyone. You can even setup a broken SPF record that disallows office 365 email and for the most part, everyone will still get your email.
That angers me so much. I had same IP address and ___domain for 15 years. Never a spam was sent from it, since the same address was used for NAT in home network I also blocked outgoing SMTP (forcing to use my SMTP instead) for cases that a PC got a virus and starts sending spam.
Things worked fine, but I think 2 years ago I realized that my e-mail started going to a spam folder. Fortunately adding SPF/DKIM appeared to fix it, but it feels like it is getting harder and harder now to have own mail server.
I would probably gave up, but it's infuriating to me that from courts rulings if your mail is handled by 3rd party, the 4th amendment no longer applies.
Not that I'm expecting it or anything like it, but running my own mail server means I'm the one who gets the subpoena for anything that might be on it. Google/Microsoft giving Third-Party Doctrine-driven open or nearly-open access to every email on their servers for any purpose is not my idea of a good business decision.
People make a big deal of SPF/DKIM etc. I think you should, for the sake of best practice. But you can set yourself up with gsuite or Office 365 and pay no attention to these things, and you can fully expect mail to get through to everyone. You can even setup a broken SPF record that disallows office 365 email and for the most part, everyone will still get your email.