Yes, but with major caveats.
For a wider variety of "unofficial" or fan-made dynamic themes, community repositories are the primary source: How to get Dynamic Themes on PS3 ps3 dynamic themes download 2021
For the tech-savvy, you can install themes manually via a USB drive. Yes, but with major caveats
The dynamic theme you finally downloaded—maybe a serene waterfall, maybe a neon-drenched cyberpunk city—was never just a background. It was a proof of life. It was a statement that even in the era of streaming and subscription services, some people still wanted their console’s dashboard to feel like theirs . By 2021, the PS3 was no longer a gaming machine; it was a museum of interface design. And every dynamic theme was a small, moving exhibit—doomed, beautiful, and worth the download. It was a proof of life