Ubuntu Mate 18.04 Slow Boot and Login (Clean Install)

I recently installed Ubuntu Mate 18.04 on my old laptop. It has 3 GB of RAM and Intel Core2Duo processor.

It takes long time to get to the login screen and more waiting to get to the desktop after entering password.

I have boot screen disabled using GRUB_CMDLINE_LINUX_DEFAULT="" by changing the file /etc/default/grub.

I have tried everything described in the answers here but no luck so far !

/dev/sda3 is the partition where Ubuntu is installed. The benchmark of this partition gives average read rate 44.9 MB/s and average access time 13.28 msec, so it is not an issue with the HDD.

Output from systemd-analyze blame,

     45.669s dev-sda3.device
     33.585s systemd-journal-flush.service
     25.686s apt-daily.service
     21.490s systemd-tmpfiles-setup-dev.service
     13.915s loadcpufreq.service
     11.823s grub-common.service
     11.094s apparmor.service
     10.979s snapd.seeded.service
     10.867s networking.service
     10.325s speech-dispatcher.service
      9.986s networkd-dispatcher.service
      9.931s rsyslog.service
      9.931s gpu-manager.service
      9.930s pppd-dns.service
      9.900s apport.service
      9.480s alsa-restore.service
      9.463s lm-sensors.service
      8.987s bluetooth.service
      8.987s thermald.service
      8.951s avahi-daemon.service
      8.250s dev-loop7.device
      7.847s dev-loop10.device
      7.808s dev-loop9.device

Output from systemd-analyze time,

Startup finished in 1min 39.563s (kernel) + 1min 26.728s (userspace) = 3min 6.292s graphical.target reached after 1min 663ms in userspace

Output from systemd-analyze critical-chain,

The time after the unit is active or started is printed after the "@" character.
The time the unit takes to start is printed after the "+" character.

graphical.target @1min 663ms
└─multi-user.target @1min 662ms
  └─snapd.seeded.service @49.682s +10.979s
    └─snapd.service @1min 400ms +253ms
      └─basic.target @39.421s
        └─sockets.target @39.419s
          └─snapd.socket @39.188s +228ms
            └─sysinit.target @39.183s
              └─systemd-timesyncd.service @38.808s +371ms
                └─systemd-tmpfiles-setup.service @38.564s +174ms
                  └─systemd-journal-flush.service @4.970s +33.585s
                    └─systemd-journald.service @4.128s +837ms
                      └─systemd-journald-dev-log.socket @4.122s
                        └─system.slice @3.927s
                          └─-.slice @3.863s