I’ve been reading here for a few weeks and it’s often very interesting and you can learn something. I myself have tried several times to design something appropriate to the topic without participating. Invisible participation 
But now I have to ask something and get rid of it. I understand the two categories “pure” and “open”, but now the votes here mainly go to 2 posts, 95% of which come from an existing scene (Cone Head Shop) where an ice cream was simply added and to a scene where finished pieces from a previous participation in the contest and finished pieces from several tutorials were simply put together to make something “new”. And not to the scenes that were actually built or “challenged” over the weekend.
But sticking together existing pieces and objects has almost nothing to do with a weekend challenge, where the aim is to create something thematically specific in a certain “tight” time on the weekend. The scenes from fchar and parclite look nice, but are 90-95% “recycled”. If this is the “open” category, I can simply put assets from blendswap, blenderkit and other sources, as well as objects built earlier, together in 15 minutes and then call them “open” and then I had almost zero effort. This encourages not, to spend a lot of time thinking up and creating scenes from scratch.
If there is such a large proportion in a scene made from recycled objects, it shouldn’t be “open”, but in fairness simply “non competing”.
Otherwise it doesn’t make sense to call the whole thing “Weekend Challenge” because otherwise there is simply no challenge to a “new” scene when simply putting together finished objects or objects build from tutorials.
That’s nothing personal against the participants here, but in the spirit of a challenge or a contest, you shouldn’t just put together what you already have and enter it as participation?