"It requires that we tolerate the very worst ideas so that we don’t risk silencing the very best. "

Precisely. Sunlight is the best disinfectant the very worst ideas usually wither very quickly once exposed to it. The best ideas endure. Unfettered free speech might not be ideal, but it's the best we've got.

More often than not, censorship is coming after the best ideas, not the worst. Heliocentricity caught on in the end.