To be fair with the comparison, we should add error handling for the jQuery example:

  $.getJSON('/my/url')
    .done(data => {
      // success
    })
    .fail((jqxhr, textStatus) => {
      if (textStatus === 'timeout') {
        // connection error
      } else {
        // HTTP status error
      }
    })

And also consider the Fetch API alternative:

  fetch('/my/url')
    .then(response => {
      if (!response.ok) {
        // HTTP status error
      }
      return response.json()
    })
    .then(data => {
      // success
    })
    .catch(error => {
      // connection error
    })

Why not use fetch?

fetch('/my/url').then(response => response.json()).then(data => handle it)