According to the SAP Help Portal1, replacing the search grid in Career Site Builder with tiles achieves the following benefits:

It allows any of the mapped fields to be displayed on the tiles. You can customize the tile layout and content by selecting the fields you want to show from the list of available fields in the Search Tiles tab in Appearance Styles Global Styles (Brand)1.

It allows any of the fields on the job requisition to be displayed on the tiles. You can also use the custom fields that you have created in the job requisition template as part of the tile content1.

It does not allow users to tab through the search results. This is a feature of the grid layout, which enables keyboard navigation through the search results2. For that reason, the tile layout is not recommended for accessibility purposes3.

It does not allow users to share jobs on social media more easily. This is a feature of the Job Details component, which enables users to share the job posting on various social media platforms. This component can be used in both grid and tile layouts. References: Search Tiles Settings in Career Site Builder Global Styles, Search-Related Settings in Career Site Builder, Configuring Search Grid Settings, [Job Details Component]