Eventually I think sites will customize every URL for each user.
TikTok is quite sneaky. Sharing from their mobile app, you get: https://www.tiktok.com/t/[9digitCode]/
Only by opening the URL in a browser will you see: https://www.tiktok.com/@[user]/video/[19numerals]?_t=[alphanumericIdentifier]&_r=1…which can be sanitized.
Here’s how they took it a step further too: YCombinator.