Okay so here is what I did now:
sudo btrfs subvolume delete /var/lib/docker/btrfs/subvolumes/*
Delete all subvolumes in /var/lib/docker/btrfs/subvolumes/*
Check subvolumes:
sudo btrfs subvolume list /
ID 256 gen 78735 top level 5 path @
ID 257 gen 78735 top level 5 path @home
ID 258 gen 78718 top level 5 path @root
ID 259 gen 77508 top level 5 path @srv
ID 260 gen 78726 top level 5 path @cache
ID 261 gen 78735 top level 5 path @log
ID 262 gen 78714 top level 5 path @tmp
ID 1530 gen 78423 top level 5 path timeshift-btrfs/snapshots/2021-02-19_16-20-17/@
ID 1531 gen 78423 top level 5 path timeshift-btrfs/snapshots/2021-02-19_16-39-01/@
ID 1532 gen 78423 top level 5 path timeshift-btrfs/snapshots/2021-02-20_01-21-06/@
ID 1533 gen 78423 top level 5 path timeshift-btrfs/snapshots/2021-02-20_01-22-59/@
ID 1767 gen 78423 top level 5 path timeshift-btrfs/snapshots/2021-02-21_01-32-54/@
Looks better, feels better.
Lets run a scrub
sudo btrfs scrub status /
If you want to see what happens you can do
# -d is for --differences to show which text changed in the watched command
sudo watch -d btrfs scrub status /
UUID: d3c75445-c596-456b-b7f9-a7bc48e9126b
Scrub started: Sun Feb 21 13:07:23 2021
Status: running
Duration: 0:00:05
Time left: 0:00:59
ETA: Sun Feb 21 13:08:31 2021
Total to scrub: 135.83GiB
Bytes scrubbed: 10.52GiB (7.74%)
Rate: 2.10GiB/s
Error summary: no errors found