You need a separate page for each policy because the law says so.
Also, GDPR requires you to present the request for consent in a manner that is “clearly distinguishable from other matters.” This means that if you bundle all of your policies into one place, a user will not be able to easily distinguish between all of your requests and thus you will infringe on GDPR. Here’s a screenshot of the actual text in case you don’t believe us.
You can read more about this topic on the great blog post "Should you consolidate all policies onto one page?" from the Termageddon team.