Marking them as obsolete doesn't hide them; nor stop them being reopened if they're deemed worthwhile!
You invest some time to fill the bug and then someone decides that it's obsolete. Then, if you still care, you reopen it? Is that right?
Now what message do I get from this besides: "We don't care about your shitty two year old phone. Buy a new one now. It will be shit again in just two years. And don't bother sending bug reports. We're in the business of selling phones not fixing bugs."
Both options have the same result: no bugfix. However option #2 is a lot more transparent. Part of that transparency is your being aware that Google simply does not care.