"the personal data are no longer necessary in relation to the
purposes for which they were collected or otherwise processed"
The data you submitted to a blockchain database is inherently needed
forever for it to function, so I think there's zero chance that this
will be interpreted as to make Blockchains illegal.
What might happen is that this in combination with the "Conditions
for consent"[1] will force people who ship blockchain software to have
prominent warnings saying that you're about to ship data that'll be
public forever.
What might happen is that this in combination with the "Conditions for consent"[1] will force people who ship blockchain software to have prominent warnings saying that you're about to ship data that'll be public forever.
1. https://gdpr-info.eu/art-17-gdpr/
2. https://gdpr-info.eu/art-7-gdpr/