Not convinced by the e-mail analogy rebuttal. There are plenty of small e-mail providers thriving alongside the giants.

Indeed. It's a bit of fake news that the e-mail market is dominated by a handfull of big players. It's enterely possible to self-host a small e-mail server and have to e-mail accepted without problems. Of course, don't run and open relay, and make sure your reverse dns and DMARC and DKIM records are correct.