The problem is that most (all?) site subscriptions now are all-or-nothing, and even if you do like a site, you probably like several, and paying $10-$30 per month (or whatever) each for even 5 different sites starts adding up real fast.

If sites were to offer an "article bank", it might be more compelling: you put in $X and that buys you Y articles, which you can read over the span of days, months, or years. But no one seems to be doing that, probably because they believe the economics of breakage is better.