Depends of your culture. By the comments here and my experience hair as a symbol seems relatively important in the US, but maybe that’s due to heavy marketing from pharma companies. Some other countries have preferences for short or very short hair[1].

Also regarding attractiveness don’t be fooled, it’s marginal compared to being in good shape and how you behave.

[1] https://www.quora.com/Why-do-many-men-in-Eastern-Europe-Serb... (not a very scientific analysis but it illustrates the point)