Yeah it’s weird, there’s plenty of examples of what people would consider “profitable” non-profits: For example Mozilla Thunderbird pulled US$6 million last year in donations alone, with the average donation being US$21, I think.
Mastodon, another non-profit, while not quite as lucrative, pulls in around £24,000 a month on Patreon donations alone, not counting any outside sponsors or Open Collective donations, and so on.