I believe protocols that need giant transaction generally don’t just store data, they really do need large scripts. If they only needed to store data they could easily split it across multiple smaller transactions.
Regarding storing data in the coinbase, it occurs to me that if CTV is activated, we might be able to get away with severely restricting the size of the coinbase, as mass payouts can then just be trustlessly moved off to a subsequent, non-coinbase transaction.