As for "everyone benefiting from training data" - sure, but the AI companies are not investing Billions of dollars out of the goodness of their hearts, it is towards one and only singular goal of making profits (at some point). People might be sympathetic to these AI companies if they at least behave decently - they take everyone's work (text, software, fiction, music, images, videos...) without paying a penny to anyone. If they take everyone's work for free, they should give away anything that is built on that work also for free. This is before we even get to environment, privacy, hammering sites by not respecting robots.txt etc issues.
If I stole all veggies from your garden but spent time/money/effort making a meal, I should at minimum share it with you for free, no? Even if I spent my own money making the meal, it was made from stolen raw material...