Villagers and iron golems use the "minecraft:preferred_path" component to make them try to avoid certain kinds of blocks when generating paths. The list of blocks with pathing "cost" has not been updated since before the nether update. Based on the kinds of blocks in the list, many new blocks added since 1.14 should probably be added. This would include the following types:

• Nether wood planks
• Stone type blocks (e.g. blackstone, deepslate, calcite, etc.)
• Brick-style blocks (e.g. quartz bricks, blackstone bricks variants, deepslate bricks, etc.)
• Slab and double slab blocks (e.g. blackstone slabs, copper slabs, deepslate slabs, etc.)
• Light-emitting blocks (e.g. shroomlight)
• Tinted glass

It's also not clear why the current list includes stone but not any kinds of ores, glowstone but not sea lanterns or jack-o'-lanterns, and blocks of redstone, gold, diamond, etc. but not blocks of iron.