I wish there were more M.2 cards beyond just SSDs and wireless NICs. The idea of a small form factor PICe interface is underutilized and things like hardware codec accelerators can keep laptops with older processors usable with new standards for longer. It’s sad how PCMCIA had an entire ecosystem of expansion cards yet we somehow decided that the much higher bandwidth M.2 is only for storage and networking. Hell, do what sound cards in the 90s/00s did and have M.2 SSDs specifically designed for upgrading older laptops that also have built in accelerators for the latest media standards. Hardware acceleration is energy efficient and can probably just be bundled into the flash controller like they’re bundled into the processor, and unless you have a top of the line SSD you’re probably not saturating the M.2 interface anyway.

Mostly yes but there are functional differences in convenience. For example the standard upgrade process is completely manual. You have to disable third party repos. You have to change the repos. You have to check if you have space. You have to remove obsolete oackages. And more. On Ubuntu, the software update tool does all that, eliminating a lot of possibility for error. To an exoerienced user, the Debian process is fine. A novice would have plenty of opportunity for frustration and pain.