What are the Benefits of Apple Music subscription?

Apple Music gives you the ability to stream, or download for offline listening, songs from a large library as long as you pay the subscription. You could purchase individual songs from the iTunes Store for permanent ownership, but it would cost you a fortune to download the thousands of songs available in Apple Music. However, because it's a subscription service, if you stop paying you will lose all access and any downloaded songs will either disappear or not play; and you can't copy songs to another device (you have to download them again) nor burn them to a CD, for obvious reasons.

If that way of working suits you it's a good deal. There are other online services which are broadly similar - Spotify, amazon Music, Google Play Music and so on - it would be up to you which of these you find most suitable. The conditions are likely to be much the same.

I view it as a listening and a pre-purchasing sampler.

A sampler that’s well integrated with iOS, iPadOS, macOS, and CarPlay.

It has introduced me to a number of wholly new and unfamiliar artists, and to new music.

It’s also helped me decide which albums I’ll purchase, and which I won’t.

If your tastes and preferences are more consistent, maybe it’s not for you?

YouTube, Amazon, Spotify, there are competitors.

One assumed “dud” album purchase ~covers the monthly.

There used to be a trial. Try it?

There are loads of choices, from Spotify to Pandora to Amazon to Yahoo. I'm not going to compare the services for you, but you can read about Apple Music and what if offers here to see if it meets your needs --> https://www.apple.com/apple-music/

Compared to?