Technology

IIRC, they have hybrids with a bunch of other berries that don't have thorns.

I don't think that boysenberries have thorns, though I haven't been picking them for a long time.

kagis

Apparently there are thorny and thornless variants.

https://en.wikipedia.org/wiki/Boysenberry

The boysenberry /ˈbɔɪzənbɛri/ is a cross between the European raspberry (Rubus idaeus), European blackberry (Rubus fruticosus), American dewberry (Rubus aboriginum), and loganberry (Rubus × loganobaccus).[2]

In the 1980s, breeding efforts in New Zealand combined cultivars and germplasm from California with Scottish sources to create five new thornless varieties.[5]

The loganberry:

https://en.wikipedia.org/wiki/Loganberry

The loganberry (Rubus × loganobaccus) is a hybrid of the North American blackberry (Rubus ursinus) and the European raspberry (Rubus idaeus),[1][2] accidentally bred in 1881 by James Harvey Logan, for whom they are named.[3] They are cultivated for their edible fruit.

A prickle-free mutation of the loganberry, the 'American Thornless', was developed in 1933.

The "smooth blackberry":

https://en.wikipedia.org/wiki/Rubus_canadensis

Rubus canadensis is a North American species of flowering plant in the rose family known by the common names smooth blackberry,[2] Canadian blackberry, thornless blackberry and smooth highbush blackberry.[3] It is native to central and eastern Canada (from Newfoundland to Ontario) and the eastern United States (New England, the Great Lakes region, and the Appalachian Mountains).[4][5] It has also been sparingly recorded in Great Britain, in which it is often confused for the many other native blackberry species.[6]

https://plants.ces.ncsu.edu/plants/rubus-canadensis/

Smooth blackberry has almost completely smooth stems that are free of prickles and spines.

Probably others.