Why? CSS selectors are the normal web developer way to select content from a document. Even JavaScript adopted the approach.

xmllint can do that:

  curl example.org | xmllint --html --xpath '//some/xpath/selector' -

I'm using xmlstarlet in Alpine as a bare minimum way to scrap a webpage in CI pipeline.

This has support for both XPath and CSS selectors: https://github.com/ludovicianul/hq

There's also https://github.com/charmparticle/xpe

Also: https://github.com/benibela/xidel