Voted no.

Even today everyone could "--assumevalid" the last block hash and delete their archives, but practically the archives are still necessary for the same reasons.

standardcrypto

Technically, yes... the archive for all intents and purposes becomes a proof instead of old blocks

Practically though, not everyone would run utreexo from the same block and never go offline. Each new accumulator would have to verify with blocks, and when an accumulators goes offline for any period of time it would need blocks for the time they're offline.

bitcoin

if everyone ran utreexo, could we stop archiving the blockchan?

Technically, yes... the archive for all intents and purposes becomes a proof instead of old blocks

Practically though, not everyone would run utreexo from the same block and never go offline. Each new accumulator would have to verify with blocks, and when an accumulators goes offline for any period of time it would need blocks for the time they're offline.