The concept of an "online profile" as we know it today didn't exist until shortly after the web's inception. By that time, email had already become deeply entrenched in our digital lives.
An email address, in its essence, provides no information about the recipient and doesn't facilitate universal access to such information.
In the past, there was a "Finger" service, defined in RFC742, which could retrieve some basic information about end users. However, it was limited to actual system users. Nowadays, email users are virtual entities and don't necessarily correspond to specific end system users.
The "Finger" service may have been ahead of its time and eventually became obsolete due to security and privacy concerns. Ironically, today, very few people view their own public profiles as a security or privacy threat.
WebFinger, defined in RFC7033, attempts to modernize the same idea, but it remains somewhat limited as a generic public profile. WebFinger is better suited as a method for discovering the location of a public profile rather than a comprehensive profile itself.
Email, as a communication platform, lacks the essential framework to support a comprehensive online profile, which includes the availability of profile photos in various formats, including thumbnails and larger images. Each email provider has its own way of handling profile photos, often generating them dynamically based on the display name or using third-party databases like Gravatar. While BIMI (Brand Indicators for Message Identification) is slowly gaining traction as the accepted standard for large corporations to display their logos in emails, there hasn't been a similar proposal for regular users.
There's a clear online demand for more robust social profiles associated with email addresses. However, the email protocol doesn't currently support such profiles, and it's challenging to extend it in a way that accommodates this need without utilizing centralized services.