Tip: If you’re worried about blockchain bloat and UTXO set growth and want to keep the chain feasible to validate for small devices, a Bitcoin block 100% full of OP_RETURNs consumes the entire 4WU (weight units) allowed per block, while only filling up the 1MB base block with actual data.

This amounts to a -42% block size decrease relative to current average block sizes. Hurray! This helps with storage requirements and reduces bandwidth to sync a node.

OP_RETURNs are also by default *not* added to the UTXO set, so there are less disk I/O (read/writes) which reduces the wear and tear on your SSD or HDD (only 1 UTXO is added per block - the miner reward) or decreases RAM requirements for those who keep the UTXO set in active memory.

Nodes also won’t have to compute those pesky SegWit merkle roots for these blocks, which your CPU will be happy to skip!