This is a Gnome-Dependent service. As such, toggling it does not work so easily.
You can mask the service to stop it from indexing:
systemctl --user mask tracker-extract-3.service tracker-miner-fs-3.service tracker-miner-rss-3.service tracker-writeback-3.service tracker-xdg-portal-3.service tracker-miner-fs-control-3.service
Then run:
tracker3 reset -s -r
A reboot is required to see the change.
You can start the service running again by unmasking it:
systemctl --user unmask tracker-extract-3.service tracker-miner-fs-3.service tracker-miner-rss-3.service tracker-writeback-3.service tracker-xdg-portal-3.service tracker-miner-fs-control-3.service
tracker3 reset -s -r
As above;
A reboot is required to see the change.