I think there's two issues at work with your comment mikie. The first, which many historians have spoken about, is that the lost habits of letter and diary writing mean that much less material will be available for historical analysis in the future. Email archives aren't as common as boxes stuffed with old letters, and email archives typically have much more worthless stuff in them. The second thing, the changes in storage media over time, I think isn't so much of a problem. There used to be lots of stuff stored on 8 and 5.25 inch floppy disks. They're not lost to the future, that worth keeping was migrated to later generations of storage media. Places like the Library of Congress and National Archives are digitizing many parts of their collections to protect the availability of their contents for the future. All that stuff gets rolled forward as technology changes.

Create the PDF...save it to your local machine...drag/drop it to the flash drive...what could be simpler? Am I missing something?

So long as you've backed up any important data files, I wouldn't fret about losing these antique programs. There are many choices of free and easy to use software you can press into service in a flash. Even Google Drive (formerly Google Docs) offers free software-like apps for word processing, presentations, spreadsheets, etc., that are completely compatible with current competing programs (which what you now have may not be). And, file backups are unnecessary (unless you're paranoid), Google keeps your files in their proverbial "cloud". To replace your (almost) 10 year old version of Quicken, try Mint. Now owned by Intuit, it's free, highly recommended and widely used. Play with it now, switch over on Jan 1, and wave goodbye to Quicken 2003. Or, get a new Quicken, it's not that expensive and it'll serve you for another 10 years.

Bigger question is are you looking for backups or to transfer the files around? If you want backups, how privacy conscious are you? If you don't care about sharing your videos, there are literally dozens of cloud services that can store or back up your videos, some for free, some for a fee. Many of the backup services can also back up any files on your computer, and make them available to pretty much any other computing device, OS etc... If you're privacy concerned, make sure you have multiple local copies of any files you want to back up. Flash drives are great for transfers, i.e. temporary storage while moving files around. They're not great for archival, they do tend to fail with no warning at all. So either have 3 or more copies on different flash drives, or use a different backup method. There are lots available, again at all different price points. In any case, you want multiple copies. Here's where DVD-Rs are useful - they are write once, so they can't be accidentally erased, they now are very cheap, so you could have 20 or more for the price of a 4GB flash drive, and if stored in a cool dark place, usually last at least a couple years. There are more expensive archival ones that claim to last 70 years, though I'd probably still check every few years if I really cared about the data, if only to migrate to current formats if necessary.