By not using Cloudflare your website will be indexed by everyone. The gatekeeper aspect only applies if you use Cloudflare to distribute your website (and even then Cloudflare offers options to control this bot shield thing).
So what then Cloudflare can use all these websites as leverage against Google, OpenAI and Microsoft? I kind of want my content to be indexed.
If you want your content to be indexed, simply don't use Cloudflare. Host your own servers. Use a different CDN if you want the benefits of Cloudflare's networks.