You'd get little to no traction with that if you frame it as a tax, leaving aside that many potential allies for such an approach would object to enshrining the characterization of copyright as "property". (Also, income earned is already taxed.)

Now, on the other hand, if you phrase it as a renewal fee, that would go over much more smoothly. Patents, for instance, have maintenance fees required at 4, 8, and 12 years, and they double each time.

I'd love to see, as a step towards limited-duration copyrights again, an exponentially increasing scale of renewal fees. For instance, after the first 5 years, it could cost $1000 for the next 5, $10k for the next 5, $100k for the next 5, and so on. (Throw in a grace period where all existing works get 5 years from the date this is passed, so people can adapt, and have time to evaluate what to renew.)

On that scale, after 5 years, any work producing value would be worth renewing. Some works will be worth renewing for 20 years. Incredibly high-value works might be worth renewing for 30 or even 35. But there'd be a serious tradeoff there; is it worth spending that much to renew the copyright of an old work, or to create a new one that grabs people's interest?

And as a bonus, abandoned works that no longer have anyone around to care about renewing would move into the public domain.