Imo, mempool.space, mentioned by Charles-Tim is far better and more user friendly. It shows the fee rate you need to pay for a low/medium/high priority transaction directly without having to analyse the chart. Also, and if my memory serves me right, there have been times when jochen-hoenicke.de showed wrong fee estimations (higher than what is actually needed).

Finding a block doesn't necessary mean the network will become less congested. It also depends on the number of newly broadcast transactions.