For Gdocs, Edit access can be changed to Viewing to avoid unwanted changes.
How can that be done for Gsheets?
There's no button in the UI for it, but there is a "Preview" mode available for Google sheets. To get to it you need to edit the URL.
The URL of a sheet in normal editing mode ends with something like ...sOmE-lOnG-ID/edit#gid=1234567
. Remove the /edit
and everything after it, and replace it with /preview
. Hit enter to refresh the page.
It will load a data-only view, no toolbars or anything. Useful to avoid making any changes, though unfortunately there's no commenting feature like Docs has.