For a start, it's a lottery. 2000 people who meet very broad but generally fair eligibility criteria (https://www.gov.ie/en/department-of-culture-communications-a...) will get no-questions-asked income regardless of their skill or importance as artists, these being qualities that are both highly subjective and not fixed in time.
So you can be anyone – rich, poor, or something in between – and still be eligible for it. All you have to do is meet the criteria, which were created in consultation with artists.
Also, what is an artist? Thankfully that's not for me to say, because I have quite a narrow view of what art is, and that view would certainly exclude some people who were successful in the pilot.
My partner has been struggling to make an income from her art for over a decade. As she is a working artist under the pilot definition, she qualifies for the lottery even though she runs a small business (to be precise, she's self-employed – making and selling her art full time. There is a reasonable chance that you have seen it). She also thinks that the government could take many other practical steps steps to make life easier for artists, but that taking a small amount of money and giving it to random artists has a huge potential upside: practically no effort, many benefits.
I know several artists whose paintings will genuinely be hanging on walls for hundreds of years. Or prints. Or photographs. Most make ends meet, and one or two are comfortable. Their work ranges from truly amazing to decidedly mediocre (in my opinion). Did any of them get this magic lottery? Yes, some did. Others (including my partner) did not.