E7 - Implications of Apple's App Tracking Transparency (ATT)

Apple recently launched a new privacy feature in iOS 14.5 that requires apps to get user's permission to track them cross-apps. And 75% of the users have opted out of being tracked, this has caused a big ruckus among advertisers and platforms that heavily rely on advertisement as their main source of revenues.

Is this really as apocalyptic as what people make it up to be?