Building new capacity takes years. The idea is that the market is reliably cyclical, so you should expand when there is a downturn, when costs are low and you can afford the short-term capacity hits that expansion causes (fe. when you divide productive teams in two and fill both halves to full strength with new hires).
If you prefer. But we seem to have gone from "undersupply in a boom" to a strategy of oversupplying so aggressively that manufacturers would finish ramping up supply well before the boom before it even happens. And that would be a better strategy.
