I don't think that it works this way. If bounce rate matters for you, because your website is part of sales conversion funnel, then you do not benchmark against random "average" website like HN, because you do not build your site the same way, your audience is likely different from many different angles and you cannot really measure the response time under representative conditions (because you likely do not know them). The only sensible benchmark you can have is the performance of your own website. It makes sense to collect some low hanging fruits, but further optimizations generally make sense when you have enough traffic to reach statistic significance in A/B tests. And those tests will not always result in more optimized version, because content matters too and better content may outperform faster version in terms of conversion, so it will often be two steps forward and one step back.