Magento 2 standard design theme (Luma) does not use a fixed number of columns for the fronend product grid.
Instead, Magento 2 uses a fluid layout: the number of grid columns is automatically adjusted to a visitor's screen resolution and a device: https://mage2.pro/t/895
It is not recommended to use a fixed number of columns because your product grid will loose its adaptiveness an will not look great on a big or a small screen.
But you can do so with CSS rules.
See how the grid columns calculations are implemented in the Magento 2 Luma: https://mage2.pro/t/895
Do you have experience of how we can alter the grid so that it isn't trying to load every attribute we have as it keeps killing our page load?
We have something like 200 attributes and it is trying to load them all with each view?