The models use past behaviour (looking at dishwashers) to predict future behaviour (buying dishwashers). Spending cash on something is a much harder signal of interest than looking at it though. So the models would be stupid to ignore that. The question of "how many dishwashers does that person need" is hard to answer and thus mostly skipped when opportunity costs are low.

Personal anecdote: Recently I cancelled an order because a better product was shown in ads post-purchase.