No, the OP_RETURN opcode is optional and not required for valid tx. I'm an interested observer of this debate but not an expert, so don't have an opinion to give. However I can offer this quote from a piece by John Carvalho earlier today : > Bitcoin offers an 80‑byte OP_RETURN field that lets users write data without polluting the UTXO set. As blockspace demand soared with Ordinals, BRC‑20, and Runes, people began hiding data in taproot leaves and bare multisig outputs, which never get spent and therefore swell the UTXO set, driving up node costs. > Relaxing, or even removing, the 80‑byte cap would invite this data back into a provably unspendable, prunable space; the chain stays neutral — every byte either pays or waits. https://bitcoinerrorlog.medium.com/how-to-think-about-data-on-bitcoin-a5a80442ef68