> If the user can search like in Youtube then how do you rank the results? That's also an algorithm.

Any ordering is an algorithm technically, so yes just "banning algorithm" doesn't work.

A better alternative could be "the algorithm must be public and reproducible by the user".

"Sort the posts of the people I follow in chronological order" you're good

"Sort the posts by the output of a blackbox trained on user data" too bad you're a publisher and are responsible for what people post.