In Monero's early history, many transactions did not include any decoys. It was extremely clear that these outputs were spent.
Could Monero prune these known spent outputs?
Here is an example transaction from block 100000:
It has a ringsize of 1 and 5 inputs:
Since all of these outputs are known to be spent in this transaction, is it possible to prune/delete all record of these outputs and their key images? Are there any significant downsides to doing so?