Unobtainable in Survival

These are impossible to get in survival mode without commands or datapacks in vanilla Minecraft.

Blocks

mob_spawner
infested_stone
infested_cobblestone
infested_stone_bricks
infested_cracked_stone_bricks
infested_mossy_stone_bricks
infested_chiseled_stone_bricks
chorus_plant
bedrock
end_portal_frame
command_block
chain_command_block
repeating_command_block
structure_block
structure_void
barrier
farmland
grass_path
jigsaw
player_head
petrified_oak_slab

tall_grass <1.14

large_fern <1.14

Items

debug_stick
knowledge_book
potion
splash_potion
lingering_potion
tipped_arrow
enchanted_book
written_book
command_block_minecart

(all spawn eggs)

Unobtainable as Item

end_gateway
end_portal
nether_portal
bubble_column
cave_air
void_air
tripwire
water
lava
fire
frosted_ice

Entities

spawner_minecart
command_block_minecart