I'm not being facetious, I'm pointing out a real problem - the market fraction accessible to a new business, that isn't reliant on the good will of some giant incumbent, is shrinking. This time it's Discord, another time it's Google ads/search blacklist, or Microsoft flagging your website or program as malicious, or Facebook shadowbanning you (or charging to show your posts even to people who explicitly followed you [1]), or Walmart extorting you for shelf space access, VISA and PayPal rejecting you..
If your move is to simply retreat, and give up all this ground, what market is left for you? People who get their news and ads by paper mail, shop only at tiny independent stores, paying in cash? How many businesses can survive with ~5% (a generous estimate of the described market's relative size) of their current traffic?
[1] https://www.bentbusinessmarketing.com/why-your-fans-arent-se...
And it's bigger than software. This is just vertical integration; both your suppliers and your customers will ask if they can replace you. As they should. If your only value is as a middleman that your upstream supplier can easily replace... well, that's not a lot of value.
You're being facetious, but OP is right. For software platforms, this has been a constant. It happened with Twitter, Facebook, Google (Search/Ads, Maps, Chat), Reddit, LinkedIn - basically ever major software platform started off with relatively open APIs that were then closed-off as it gained critical mass and focused on monetization.