Spotify has the most global market share of any music streaming service. In 2018, Spotify accounted for roughly 70% of global streaming revenue and 33% of all recorded music industry revenue. Given there are only two other sizable music streaming services, this is a hint that there are large barriers to entry in this industry.
The only three companies with meaningful market share are Spotify, Apple and Amazon: one dedicated streaming service founded in 2006 and two tech giants. Spotify has the benefit of brand name, reputation, network effects, and being synonymous with online music. Apple and Amazon have the benefit of hundreds of millions of users they can cross-sell music to. It would be much more difficult to start a dedicated streaming service today now that Spotify already exists and has scaled globally to over 200 million users.