Back when the JPG image format was introduced, it made a lot of sense to reduce the file size, even accepting a loss in image quality, because files were being downloaded over a slow and expensive modem connection.

In today's world, file size is no longer a concern, at least not regarding JPG where it seems silly to save 45kB on a photo. But my image editing apps still prompt me for the desired compression level when I save a file.

Does it still make sense to go with the default 85?
Why should I not crank it up to 100 for all files?

Update based on comments:

• For web work, I might use PNG instead. But every smartphone and camera produces JPG files. The question arises when I save these edits.
• Audience is my own harddisk. We're talking photos, 2-5MB apiece.
• Chroma, subsampling, DCT - sorry, never heard of it. I'm a home user, not Photoshop guru. For the record, I use Paint Shop Pro on Win, and Gimp on Linux.