I assume the 5 years means starting with a Bachelors. At least in the US, it's fairly unheard of to finish a PhD in 3 years or less.
Between classes, teaching, and genuinely getting things done, it's not a fast experience.
Also, you probably arent making a ton more unless you go for an industry job...which is a little bit the opposite of the Platonic independence supposedly at the heart of the training method.
But very few people I know want to be a PI.