Before Drupal 8, it was rather difficult to easily build a responsive grid in Views. This was largely due to the fact that Drupal 7 Views did not use DIV. The consequence was that in order to build a responsive grid with Views, it was necessary to employ the use of contrib modules such as Bootstrap Views.
Fortunately, Views grids in Drupal 8 core have been replaced with DIV so you can just create responsive grid without the need for any contrib module.
- Create a new View and chose Grid as the formatter.
- Go to the grid View
- Click on format - settings
- Set "Number of columns" to 3
- Uncheck automatic width
- Set "Custom column class" to fx col-md-4 col-xs-12
- Set "Custom row class" to row
- Uncheck: "Default column class" and "Default row class"