Two rounds that can vanish
In most sports a poor start can be repaired gradually across a long contest. In stroke-play golf, a poor two days can end the week outright, and nothing scored afterwards counts at all. That asymmetry means the cut is not a footnote to the tournament but a second contest running inside it, with its own tension and its own incentives, decided well before the outcome that most viewers are actually watching for.
The bubble changes the calculation
Players hovering near the projected cut line face a different decision tree from those comfortably clear of it or hopelessly behind it. A player one shot outside the line late on Friday has strong reason to attack a risky pin, because missing the cut by one shot or by four carries an identical result. Someone safely inside the line has every reason to protect the position they already hold. The same hole is therefore played completely differently depending on where a player sits relative to a number that is still moving.
Setup as an amplifier
Organisers can sharpen or soften this tension through setup alone. Tucked pins and tight fairways widen the spread of scores and make the cut line more brutal and unpredictable, while a gentler setup compresses the field and turns the cut into a formality decided by small margins. Neither approach is wrong, but each changes what viewers are rewarded for watching: a hard setup produces drama around the cut itself, a soft one shifts that drama to the weekend leaderboard instead.