These do happen every once in a while, when there are spending attacks or sometimes just like that when there is plenty of txs and the block mining is slow, there is no thing much you can do other than using high fees and waiting for blocks I guess.
I have the sense that this thread was not really about solving the transaction delays from a few days ago with a larger fee, even though some posters had been proposing that providing a higher fee could have partially solved their transaction delay issue.
I doubt that providing a higher fee would have solved the issue from a few days ago, because it seems as if the problem of the delays during that period was due to some kind of spam attack on the network that delayed ALL transactions on almost an equal basis and no matter what the fees. Sure, there may have been some outlier transactions that got processed, but for the most part, NO transactions were being processed.
After about 30 hours, once the attack seemed to have been over (or addressed or gotten under control), then transactions began to go through and the back log of the mempool came back down to more normal levels, which came down pretty fast (about 12 hours or so), and thereafter transaction times returned to taking well under 1 hour with normal or even relatively low fees.