Is there any way to confirm this? Or are there examples of artists who made a significant amount of money from NFTs? I understand its potential benefit for artists, but I mostly remember already-rich corporations (e.g. UFC) using them as another way to extract money from consumers.

That's not really what happened. Some people who had invested in companies that would make money if NFTs went up in value chummed the waters by buying NFTs for huge amounts, convincing a lot of people that NFTs were going to be great investments. Then celebrities with an interest in the scheme pumped up the value too.

That convinced a lot of idiots to "invest" in NFTs, then eventually the bottom fell out of the market.

As for artists, some made some money, but most of the money went into shit like "bored apes" which were algorithmically generated.

The smart criminal understands the value of diversity.