WHY are cookies not encrypted on api routes by default? Any reason to be aware of?

Laravel documentation says that laravel cookies are always encrypted. (https://laravel.com/docs/5.3/responses#cookies-and-encryption)

I realized that on the spark setup the middleware that does EncryptCookies is only part of the web middleware group and not on the api middleware.

Is there a reason for that?

Background of question: when using cookies in a mixed setup with api calls and web routes reading cookies causes problems. Reading a value from an encrypted cookie via api request returns null and vice versa.