>, it's actually about 50% cheaper to get a taxi from SeaTac to the city than to take a Lyft or Uber.

That type of ride from a "hub" where a bunch of taxis congregate to take the next passenger -- such as SEATAC airport -- is optimal for traditional taxis and can be cheaper. But using Uber for suburb-to-suburb routes away from any hubs is cheaper than taxis and I tried to explain why that happens: https://news.ycombinator.com/item?id=30660517