Are Uber and Lyft tech companies?

It depends on how you define tech companies.. Their main product is a transportation service, but there is obviously a lot of tech involved.

Similarly, there are websites which deal with selling clothes, so you could ask if they are in retail/fashion or in tech.

A couple of years ago, I worked in a startup which was involved in the local independent music scene. They organize events, did ticketing and have a online music magazine, with apps. Some people call it an entertainment/music company.. Some people call it a marketing/ad agency (because of what it offers its clients). And geeks like me called it a tech company.

It depends on your perspective.

Algorithms are not the only thing that make a tech company, but without scheduling, multiparty-route-optimization, or other clever algorithms central to their business, Uber and Lyft are just transportation companies that capitalized on the fact that young people like to call cabs with a button... instead of a phone call.