You're forgetting the offset from undercutting. The cars don't need to be within 1s on track for it to matter - you could be within 4s and that extra 0.5s in th

You're forgetting the offset from undercutting. The cars don't need to be within 1s on track for it to matter - you could be within 4s and that extra 0.5s in the pit stop costs you the position if you pit later. Un-lapped 'traffic' is also critical. If you're trying to find a gap to pit into and it's tight an extra second could put you behind a slow car and cost you 'real' positions later.