If Netflix can offer unlimited streaming of video content, which is often more expensive to license than audio content, for $15/month then Tidal should be able to figure out how to do audio for $20/month.

I like Tidal, and they do have a reputation for quality of content even if the business side has been a bit flaky.  I have a feeling someone will step in and acquire them if things get dire.

If they fail, there's always Deezer and the upcoming US launch of Qobuz. 
It may well be the case that the fees are not enough to cover expenses, and royalty payments are a fraction of what they use to be.  At its peak, the worldwide recorded music business made four times what it makes now.  Pirating has cut very deep into profits.  If you sell CD's or vinyl or downloads or a subscription to a streaming service, you have to price it low enough that someone will pay instead of stealing the content.  I hope Spotify can successfully alter their business and get back on track; it would be worse for buyers as well as musicians if they, and other services, fail.
It's not about making money, it's about getting subscribers.  As long as people are signing up for the service they will have investors backing them.  Not paying people who you owe money to is a time-honored way of doing business with no associated long-term effects.  Just ask our President.  The title of this thread is fake news!