if its an intended feature then please disregard
i presume netherack and nylium blocks are supposed to have the same behaviour as dirt and grass blocks, however i am able to mine nylium blocks without silktouch. (diamond pick with no enchantments)
NOTE: This wasnt the case in 20w14a
Environment
was a fresh nether world, less then 5 minutes after first entering nether, nothing constructed besides some cobble around my portal
Duplicate of MC-172197.