This resolves to Vox Future Perfect's judgement of this question.

From the start of 2015 to the end of 2023, the share of US eggs from cage-free chickens leapt from around 6 percent to 39 percent. It was the result of persistent campaigning from animal welfare advocates that stretched back to the early 2000s — primarily lobbying state legislatures, passing statewide ballot measures, and persuading food corporations to change their animal welfare policies. (Disclosure: I worked on the issue on and off from 2012 to 2017 at animal welfare nonprofits prior to joining Vox.)

The share of hens raised cage-free has grown by about 5 percent each year since 2019, but I’m going to predict we’ll see a slightly bigger percentage growth — 6 percent — in 2023 for two reasons.

The first is that three state laws requiring all eggs sold in the state to be cage-free come into effect on January 1, 2024, in Nevada, Oregon, and Washington. Their populations combined account for around 5 percent of US egg consumption. Even more state laws go into effect at the start of 2025, covering around 7 percent of US egg consumption. However, I’m not predicting a 12 percent increase because some of those states’ egg supply is already cage-free. Plus, some of the ramp-up to these laws may already be reflected in recent data or won’t be reflected in the end of 2024 data.

Second, most food corporations that committed to going cage-free set a 2025 deadline. Many companies have or will meet it, but many won’t, especially grocers, which sell a big portion of the US egg supply. Two of the biggest — Kroger and Walmart — have already backed away from their 2025 deadlines. But speaking from experience, nothing spurs action better than a deadline, so we may see companies inch closer to their goal than they did in previous years.

The switch from a cage farm to a cage-free farm represents just a marginal improvement for a hen’s life, but it’s remarkable that a tiny, poorly funded movement has been able to change a fundamental practice of a massive industry. I’ll bet that in 2024, the rate of change will be a little faster than in recent years. —KT

Vox's prediction was "70 percent"