I won't use Uber/Lyft because I disagree with their business model. Both companies started out by ignoring laws through false claim of calling themselves "technology" companies. Additionally, Uber has been plagued with numerous instances of what I consider to be unacceptable behavior by company leadership.
Also, remember that you're getting into a private vehicle driven by an independent contractor who may not have been interviewed in person by the company. You have no idea whether that vehicle has been properly maintained.
I feel much more comfortable in a taxi because I feel that the vehicle is subject to routine maintenance and it's operated by an employee of the company. Although I can't tell you about Mears, the local taxi company I use has video cameras that record the first 5 minutes of every trip.
For the record, my decision to not use Uber or Lyft costs me time and/or money. I don't own a car. If I need to get somewhere, I take the bus (which costs me time) or call a cab (which costs me money) when compared to Uber/Lyft. So, I am putting my money where my mouth is.
That said, I recognize that some people don't share my viewpoint. So, don't read this as me trying to convince you not to use them. Although, if you're undecided between the two, go for Lyft. Uber has had many, many ethical controversies over the years.