The phrase "faster horses" means that instead of creating something completely new, people should focus on improving or making incremental changes to existing ideas or inventions. Full definition
By focusing on user experience are destined to simply get faster horses? (slaw.ca)
His line is a kissing cousin to Henry Ford's famous quote: «If I had asked people what they wanted, they would have said faster horses.» (inc.com)
For instance, the Derby, while one of the oldest consecutively running sports events in history, is a relatively recent incarnation of the enduring human passion for riding fast horses in competition. (edutopia.org)