Open source is not a business model, and I think the expectation to get paid for open source is a bit disingenuous. There is also the ideological aspect of free as in freedom licensing, while it doesn't exclude monetization, often detracts from the incentive to pay for software.
To play the devil's advocate, I would suggest that there is price discovery at play here and people + corporations are willing to pay for what they get value out of. Which is suggesting that many companies don't get much value out of Babel or it is one of many tools utilized in a toolchain. The value proposition is to be able to run new JS in old JS runtime, which may be less valuable now than it was 5 years ago, since evergreen browsers exist and outside of stale corporate environments, most browsers are auto-updating now.
To play the devil's advocate, I would suggest that there is price discovery at play here and people + corporations are willing to pay for what they get value out of. Which is suggesting that many companies don't get much value out of Babel or it is one of many tools utilized in a toolchain. The value proposition is to be able to run new JS in old JS runtime, which may be less valuable now than it was 5 years ago, since evergreen browsers exist and outside of stale corporate environments, most browsers are auto-updating now.