Taxi workers are no longer considered independent contractors.

Independent contractors aren't covered by the NLRA. So they don't have the right to have a union and a company is not required to deal with a union and can retaliate against independent contractors for even discussing being in a union.

Now what is considered to be an independent contractor has varied over time. Generally when conservatives are in office, the definition expands to exclude more people from protection. And more liberal presidents put in more liberal heads of the NLRB that are more likely to shrink the definition.

There were several factors that led to the taxi workers alliance creation and becoming recognized as a union. One of the biggest ones is that they used the medallion system and other similar laws to their advantage in that if enough of the medallion owners were refusing to work, then they couldn't just hire new workers. There aren't exclusivity laws like that in very many other industries, including delivery services, to use to put pressure on employers.

And it took like 20 years to be recognized as a union when the NLRB declared that taxi workers are employees and not independent contractors in 2015.