If one single entity is indeed capable of spamming the network for almost no cost wouldn't some Proof of Elapsed time help preventing or at least make such spam attacks much more inefficient?
I am inexperienced in blockchain programming and it's just an idea that occured to me spontaneously after seeing people suggesting raising the fees.
I think u/Tystros has very early spotted a more possible explanation
The flood XMR attack is perpetually very costly, has to go on for ever to be effective, and has to increase on par with increase in real usage. Imhv, we can not exclude it, but this is not the case atm.
The number of people latching on to my public node this morning was around an all time high.
IMO, a lot of Monero is on the move. One reason could be a ransomware attack against some entity, demanding a large sum of money in Monero. Not every ransomware attack is made public.