As for the reason for these higher temperatures, your Digital Trends article says this:
Well, open and accessible components certainly may be one of the culprits. Multiple fans, more heat pipes, large heatsinks, extra vents in the chassis, and other kinds of heat spreaders are all additional techniques laptops use to cool these components. The Framework Laptop is limited to just a single large fan, a couple of heat pipes, and some small openings along the bottom of the laptop for airflow.
I share your concern, by the way.