Right, I am specifically saying that you cannot “spin up a mail server today for pennies and start handing out my email to Average Joe”. It will fall in their spam folder and you will have to jump through many hoops to make sure that it actually gets delivered as expected.

I experienced this specific issue you desribe myself. Turns out my server configuration was out of date and not following best security practices.

the big players creating ways to ensure that the small players aren’t playing on equal terms

This has really not been my experience. Again, in my experience the only “barriers” I have encountered relate to de facto upgraded security protocols. Which is totally reasonable and within reach of any competent server admin (hey, if I could figure it out, anyone with a bit of knowledge can).