> However, I guess they have become the major player now and certainly try to optimize the world towards their business model.

I don't think that's it, and I think the explanation is much more simple and straight-forward.

Cloudflare established a very successful business model around a straight-forward, very transparent, no-bullshit CDN. Now, they started offering other cloud services build around their CDN. Cloudflare Workers kind of extend their CDN pipeline to allow clients to run arbitrary code to customize caching logic, but it turns out their function-as-a-service model is exceptionally good, and higher-level services like email are a low-effort way to meet existing needs.