Ohh they hired a toxic marketer.
The way I read it, you need an account to see the source code but you don't need to pay unless you want the asset collections or whatever that is.
I may be wrong and I won't read further right now, but the screen IS designed to make you believe you need to pay.
Entshittification incoming?
That's how the blender open movie projects have been organized for a long time. If enshittifaction was coming it would have happened 10 years ago. In few of the earliest ones it was a bit different with more of the files being publicly downloadable. But even then they where pre-selling DVDs containing best quality videos, commentary from artists, tutorials and all the production assets. Almost 20 years ago when first open movies were released internet speed was orders of magnitude slower. So while you could in theory download various production files it was less practical. Blender studio subscription (previously called Blender cloud) has been a thing since ~2014, long before the recent increase in popularity and sponsors.
I am talking more about the the context of open movies, but the few game projects are done in similar manner. Although software licensing makes things a bit more messier.
Some people pay money to fund a team of professional artists and maybe even 1-2 software developers to work together with blender developers on the open movie project in return people who paid get access to all the production files and high quality training material. In the mean time everyone else still benefits from the new features and other software improvements made during the production of movie.
One of the big problems with many open source software is not enough dog-fooding, insufficient user testing and involvement of professional users for the final software. Most of the developers are programmers not professional artists, and most of the artists are not programmers making it hard directly contribute or even communicate the feedback in a way that's actionable. Many of the professional users also don't want to waste their time with half finished open source software resulting in chicken and egg problem. Blender open movie projects solve those problems.
Providing paid training materials while getting user studies on large size projects in the process of making them seems like one of best ways for more sustainable open source with less conflicts of interest compared to what most open core software does.
It's not like the the Blender foundation is diverting money from developers towards projects no one asked. People are getting exactly what they are paying for. Based on 2023 reports blender foundation gets 2-2.5 million € in yearly donations, out of which ~70% goes directly towards developer salaries, 10% other salaries and only 3% (72000) is labelled as "support studio for testing" in the previous years explaining that it's the money going towards "Blender studio" for specific work. In the mean time Blender Studio has 6500 monthly subscribers (~0.9m € yearly).