Question: Is there a general rule when displaying data in a grid form versus a simple tabled list? Since modern screens tend to be wider now, it makes more sense to me to start utilizing grids instead of normal lists. Do grids face any UX downfalls, since they could be harder to scan or read?

Here is a sample grid layout that I am considering using for a project I am currently working on.
![Grid Layout](https://i.stack.imgur.com/aRHGK.png)

My alternative table would look something similar to this (using Bootstrap's `.list-group`):
![Table Layout](https://i.stack.imgur.com/4oWa4.png)

Alternatively, I can add a preference to choose between a grid and a list layout, but I just don't want there to be an overwhelming list of options for the user.

Answer: 
As in all design, context and content should drive presentation. The grid format could work well on mobile, when you need to reduce the content displayed, and the table format could work well on desktop/tablet, to give additional information. If you're going to have actions for each item, then I think the table view is better, as it's easier to tick off actions when they're all aligned vertically. 

One side note, I'd call them table and card view, as grid and table are interchangeable terms to developers.
The grid view might be a good solution for your case if you implement a simple filter with options like-'online','offline','device with fault' etc, I think. If you think the target audiences are more likely to view it on larger screens then the grid view might be a good option in terms of utilising space. On the other hand, on smaller screens the table is more suitable, I believe.