How do you print View fields on Twig?
After eating dinner, washing the dishes, playing around with it and reading the comments in views-view-fields.html.twig located in core\modules\views\templates

/**
 * @file
 * Theme override to display all the fields in a row.
 *
 * Available variables:
 * - view: The view in use.
 * - fields: A list of fields, each one contains:
 *   - content: The output of the field.
 *   - raw: The raw data for the field, if it exists. This is NOT output safe.
 *   - class: The safe class ID to use.
 *   - handler: The Views field handler controlling this field.
 *   - inline: Whether or not the field should be inline.
 *   - wrapper_element: An HTML element for a wrapper.
 *   - wrapper_attributes: List of attributes for wrapper element.
 *   - separator: An optional separator that may appear before a field.
 *   - label: The field's label text.
 *   - label_element: An HTML element for a label wrapper.
 *   - label_attributes: List of attributes for label wrapper.
 *   - label_suffix: Colon after the label.
 *   - element_type: An HTML element for the field content.
 *   - element_attributes: List of attributes for HTML element for field content.
 *   - has_label_colon: A boolean indicating whether to display a colon after
 *     the label.
 *   - element_type: An HTML element for the field content.
 *   - element_attributes: List of attributes for HTML element for field content.
 * - row: The raw result from the query, with all data it fetched.
 *
 * @see template_preprocess_views_view_fields()
 */


{{ fields.title.content }} worked for me. In hindsight it's very similar to the D7 code, duh, lol. 

For other fields:

{{ fields.machine_name.content }} What's the machine name? You can find them under the Machine Name column in the Manage Fields of your content type or block.