Everyone doesn't agree that GIMP is "inferior" to Photoshop. They serve different markets. GIMP doesn't have as much manpower to put into the super high-end features, like tightly integrated RAW editing, but then people aren't paying 700 bucks per copy of GIMP either. GIMP does have features that Photoshop doesn't have (like a Python scripting interface) that makes it better for some use cases. For generic bitmap editing, either one works just fine, though GIMP is better for the casual user in most cases as it allows you to save your 700 bucks and put it toward something important.
LibreOffice is much the same, but I think the gap is actually much smaller. Microsoft Office does have some niche features that are not replicated by LibreOffice, and Microsoft has made their formats for annotations and other features that should be simple sufficiently complex to make import/export difficult, but LibreOffice in my experience is faster and has more of the features that I like and use (at least more accessible; apparently someone has said Office now includes direct PDF export, so that's nice). I use LibreOffice even if I'm using a computer with Microsoft Office installed. As with GIMP, in some specific cases, Word may be required, but in most cases LibreOffice works just fine and saves you hundreds of dollars.
The exception here is probably Calc v. Excel, because it seems true in my experience that Excel has many more features for power users than Calc.
LibreOffice is much the same, but I think the gap is actually much smaller. Microsoft Office does have some niche features that are not replicated by LibreOffice, and Microsoft has made their formats for annotations and other features that should be simple sufficiently complex to make import/export difficult, but LibreOffice in my experience is faster and has more of the features that I like and use (at least more accessible; apparently someone has said Office now includes direct PDF export, so that's nice). I use LibreOffice even if I'm using a computer with Microsoft Office installed. As with GIMP, in some specific cases, Word may be required, but in most cases LibreOffice works just fine and saves you hundreds of dollars.
The exception here is probably Calc v. Excel, because it seems true in my experience that Excel has many more features for power users than Calc.