You're not forced to use Cortana, but it's an integrated AI-based assistant, like Google Now or Siri. Bing provides the back end and stores personalization info for cross-platform use.
You can use your browser of choice in Windows 10, and your search engine of choice. Nothing forces you to use either Edge or Bing.
If you choose to use Cortana then you are asking Microsoft to deliver a different type of service, which it does.
Apple and Google control their own back-end systems in exactly the same way, and Siri also "forces" you to use Bing (among other things) without asking or telling you.
You can use your browser of choice in Windows 10, and your search engine of choice. Nothing forces you to use either Edge or Bing.
If you choose to use Cortana then you are asking Microsoft to deliver a different type of service, which it does.
Apple and Google control their own back-end systems in exactly the same way, and Siri also "forces" you to use Bing (among other things) without asking or telling you.