According to an article I read on Law360 (paywalled), Facebook's Libra could never be successful as envisioned because the tax reporting burden on it will be too high. Essentially, users will constantly need to track the value of their Libra vs the US dollar to report their taxes accurately in US dollars.
Here's an excerpt:
Users hoping to pay for everyday transactions with Facebook Inc.'s planned cryptocurrency could be required to keep near-constant tax records, a major impediment to the company's dream of establishing a convenient worldwide digital currency.
If tax authorities were to consider Facebook's Libra an asset — as most do digital currencies now — then they would likely consider any exchange to be a realization of gain or loss, requiring taxpayers to keep records and potentially pay capital gains tax. To create a cryptocurrency “as widely accepted and as easy to use as possible” that “people can use with confidence and convenience in their everyday lives,” as Facebook has promised, the company would need either to create an unprecedented tax compliance program for its users, or to persuade tax authorities around the globe to change how they treat cryptocurrencies.
My question is, why can't Libra just be classified like any "points" offered by a company or group of companies? For example, I earn Starbucks points and I don't calculate the value of a Starbucks point in US dollars every time I get a coffee.