Androids are very capable these days, no argument there, but I wouldn’t credit them with equivalent functionalities of a desktop computer (and its operating system).
But, more relevant, what I was getting at is that the Librem 5’s internal components can be considered more similar to desktop/laptop (GNU/Linux) internals, with power draws and power management that is (probably?) more similar to those, due to its separate, isolated hardware pieces. Android mostly doesn’t have such separate hardware components inside, as far as I know.
The Librem 5 is also running mainly desktop programs that have been adapted for it, possibly not yet optimized to save power. Whereas Android has its optimized, native mobile apps, as well as aggressive “uni-tasking,” if I can suggest an opposite of “multitasking.”
At least, that’s how I understand it from Purism’s historical descriptions of the L5’s design. I’m no expert on any of this, of course.