kubuntu boot time

All thing systemctl does is removes couple of files:
rm -i /etc/systemd/system/*wants/NetworkManager-wait-online.service

Thank you!!! that FINALLY did it. Although, I had to find it at the location you had, but it still loaded on a reboot. Your answer made me search everywhere, and I found it two other places.
and
systemd-analyze blame
shows that it is finally gone.
Of course, now I want to weed out other services that I don't need, for instance the slowest service now is dev-sda6.device and then gpu-manager.service loading at 643ms and 582ms respectively.
the thing is, I don't know what I need and what I don't. Would there be a list of essential services?
Also, do you know of a way to just disable the service? It seems like an all or nothing kind of thing to remove the file.

I guess we both benefited, good collaboration, however, I think you would be the brains of this organization.
Yep, I have some googleing to do. I want to see just how fast this thing will boot.
Thanks again for your help.