UPDATE: The article apparently was later moved to: https://www.norran.se/nyheter/kyrkogardar-toms-nar-manga-overger-gravstenar/.
Newsletter reader Annelie Jonsson (in Sweden) sent a link to an interesting article in a Swedish news web site. It seems that Swedish the tombstones don’t remain in place forever. In most cases, a Swedish tombstone remains in place for 25 years after being installed. After that, the owner of the cemetery plot can pay extra to extend the time but a lot of Swedes don’t do that any more. The online article explains the practice.
You can read Cemeteries are emptied when many abandon tombstones as published in Swedish at
https://www.norran.se/nyheter/hostens-fargrika-skord. UPDATE: The article apparently was later moved to: https://www.norran.se/nyheter/kyrkogardar-toms-nar-manga-overger-gravstenar/.
Google Translate does convert the article into readable English. However, there may be a few minor translation errors which can easily be ignored.