What is better a band or a soloist?

I think I maybe agree with some of the points you're trying to make but what you say sounds confused, it only applies to a tiny area of "music", and you're using a lot of the wrong terms.

The term "soloist" is more often than not applied to an instrumentalist - maybe someone who plays a solo in a song or a person who plays the main melody in a classical piece of music. When applied to a singer, it would be a singer who sang the main part in something like an opera or in a choir.

What you're talking about are solo singers (often called "solo artists", although a "solo artist" could be an instrumentalist) - something quite different.

Being a singer and being a composer are two completely different things and there are very, very few "great" singers, in any field, who composed their own material. People like Frank Sinatra, Caruso, Elvis Presley, Ella Fitzgerald, Bing Crosby, Joe Cocker, Dusty Springfield, Aretha Franklin etc. etc. are considered "great" because of their singing ability. Most of them never composed anything. They are certainly "artists". A singer sings - they are not required to do anything more. An album containing songs sung by, for example, Beyonce, is is an album "by Beyonce". I have an album by The Boston Philharmonic Orchestra. They wrote none of the material, didn't arrange any of it and had nothing to do with producing or engineering it but, its "their album" - that's how these things work.

A producer is the person in charge of the recording process: the person responsible for the finished track or album. It has always been very rare indeed for a singer or even a band to produce themselves. Even The Beatles had George Martin. Nowadays it's not unusual for an album to contain tracks recorded in different places using different producers. I prefer "the old days" when an artist or band went into one studio and the whole album was recorded using the same engineer and the same producer but, times change.

Generally, solo singers do NOT "grab samples", use Autotune or do any of the other things that people object to. Nor do they use a particulat snare sound or reverb - those choices are down to the arranger and the producer (although, of course, anyone who just happens to be around might make a great suggestion).

Music doesn't "need" vocals, production or lyrics. Vocals and lyrics only apply to songs; production only applies to the actual recording of the music. If you go and watch a live performance by a solo i strumentalist or an instrumental band, you won't see any of these things.

I don't know what you mean by bands dividing "the work", or when you say it "corrolates". There are many, many bands who record material composed by other people and who (wisely) use an outside producer when recording.

I think that, underlying what you say, ther is a criticism of much of today's "pop music". I would agree with you. I find it soulless, lacking dynamics, noisy and gimmicky - it has far more to do with fashion than with style or substance. That's what people seem to want though.

However, a singer is a person who sings - they don't (by definition) need to compose, arrange or play on anything they tecord. Nor do they need to produce or engineer it. They aren't responsible for any art work used or for booking session players. They just sing.

To answer your main question, neither a singer nor a band is "best" but, generally, I'd prefer to see a band as I'm more interested in seeing a band at work than seeing a singer at work. Also, there aren't really and solo singers I'd actually want to go and see. That's just my preference though.

Band, definitely.