Every team agrees performance matters; few enforce it. A budget that isn't wired into the build is a wish, the numbers that matter are the ones that fail the deploy.
The budget for small systems is concrete: under 200KB of JavaScript on first load, LCP under 2.5 seconds on a throttled connection, no layout shift that moves a button under a thumb.
The enforcement is the point. A regression that breaks the budget is a bug, not a suggestion, and treating it that way is what keeps the numbers from drifting.
