(Carl from Obscura here)

Yeah it'd be a cool addition to combat internet surveillance but in practicality it may have a lot of problems:

1. Deteriorated performance if it's across unequal links (3G vs. Fibre WiFi)

2. Many countries have single exits to the global internet so they'd be able to assemble everything there

3. The most important plaintext data is probably in the TLS SNI which usually sits in a single packet for TLS in HTTP/3