More Powerful Alternative to Excel

I use Excel on a daily basis. For the most part, it does what I need it to do. However, there are a few instances where I just can't do what I need to, not because Excel is missing anything in functionality, but because Excel simply can't handle certain tasks if the worksheet is too large.

Usually when this happens, I've exported a large data table from another source. I am then analyzing that data to make sure matching part numbers were correctly grouped together in the other system, meaning I need to do something like highlight all duplicate values in column A and all duplicate values in column C, and then ideally be able to sort or filter by the highlighted cell color. If something in cell A is red but cell C is white, then I know those weren't correctly grouped together. Problem is, when I try to sort or filter by the conditional formatting of cell color, Excel freezes for 10 minutes or more. I can't even scroll without it locking up once the conditional formatting is applied.

Is there another program that could better handle a .xlsx or .csv in this way? I am not very technically savvy - this just happens to be a technical part of my otherwise non-technical role, so I would need it to be very easy to learn and use. Basically I just need a more powerful version of Excel.