This has been a request for years in Chromium (reported by vadi.ile...@gmail.com, Sep 30 2013):
Steps to reproduce the problem:
1. There is no option to select position for desktop notifications.
2. My opinion is for users docked windows taskbar in left right or up, they should be able to select the opision
(sic) of desktop
The final post (comment 18 by firstname.lastname@example.org, Jan 12, 2018) states:
Lowering priority since our team's priority is currently to move
notifications on all platforms to the respective native notification
centres, where supported, and Chrome has no influence over where
notifications are displayed by the native notification centres.
On platforms where there is no supported native notification centre
(Windows <10 and some Linux variants), we fall back to the Chrome
'MessageCentre'-style notifications. For these we do have control on
the location of the notifications, so we could in theory do something
there, if there is still demand for this issue.
So ATOW (2018-06-13) the priority is low and, if you want Chrome's team to spend some time on this issue on your system (one of those Linux variants, Windows 8.1 or lower) because it's annoying for you, you should voice your opinion there.