(I'm a designer at Plus) It wasn't our intention to look specifically like Gumroad, but some of the visual patterns are definitely similar. This aesthetic is making the rounds right now: https://bootcamp.uxdesign.cc/the-neubrutalism-or-neo-brutali...

We were looking for something that felt approachable and fun, magical but not mysterious. After trying a bunch of different things, this is where we landed.

They look very different to me. Maybe a similar-ish color palette is what you're seeing?

I agree, looks a lot like Gumroad