Acid3 is 100 tests but to have a browser that works on any real percentage of the internet you need to pass the over 52000 tests and nearly two million subtests [1] that make up the Web Platform Tests [2]

This is like the difference between a college degree and passing a spelling test.

1. https://servo.org/blog/2023/07/20/servo-web-platform-tests/ 2. https://github.com/web-platform-tests/wpt

Not to mention this site is clearly vibe coded and has a vague call to action and no source code available thus indicating possible vaporware.