You can’t change that behavior on the grid view itself, but there are at least 2 other ways that you can visually prevent the text from collapsing together like that.
These 2 ways would enable you to always see the properly wrapped text with its carriage returns (i.e. new lines) always visually intact:
Use Airtable’s Interfaces feature. Interfaces will always display the fully-expanded text of a long text field at all times. Some people dislike this because it can take up a ton of screen space, but in your case, it sounds like exactly what you’re looking for.
Use the 3rd-party extension On2Air: Amplify, which lets you create your own customized dashboards with the exact height & width of whatever fields you choose. You get to specify exactly how wide & how tall you want your chosen fields to be, and you also have the benefit of never needing to leave grid view to switch to Airtable’s interfaces feature.