It’s not “running Linux” that’s the issue. It’s running Linux and getting good battery lifez

And a 1.6Ghz RISC V CPU isn’t exactly “fast” in 2026 or even 2021.

You noted that it was 5 hours when powering a second monitor from its USB port. Not just displaying video from the USB port, the monitor is getting power from the USB port.

How long do you think your 5 hour laptop would last powering an external display - again not just video out, also supplying power?