This is a feature of APFS that Finder can't do much about it: local backups via the APFS snapshotting. APFS maintains a number of local backups for a period of time in a preparation (or, rather, in a hope) to permanently transfer the backups to an external Time Machine, after which the local backups are purged. If there is no external Time Machine set up, the backups will be purged after N days or under the disk pressure (free space is needed urgently).
btrfs in Linux creates file system snapshots in a similar way.
It is possible to entirely disable the APFS snapshots via «tmutil disable», but it will become impossible to restore deleted files, which may or may not be important for some.
The snapshots can also be manually deleted at any time by running a one-liner:
for i in `sudo tmutil listlocalsnapshotdates | grep '^20[0-9][0-9]'`; do sudo tmutil deletelocalsnapshots $i && echo $i deleted; done