I've just gone back to the sidelines as the mempool is not the only thing with anomalies right now. If you look at btc and most of the altcoin market, there was a huge drain of liquidity/liquidity grab market wide. Some alts/tokens dumped around 50% in just a matter of minutes...only for AMM'S to recover the price, but liquidating longs and stripping the book of its strength.
I am curious to see how the Mempool flood and the liquidity grab effects the market over this next week or so. This could effect sentiment quickly.
Also, there have been mempoool floods before, most recently around the time that Ordinals were new (earlier in the year). It costs money to spam the chain, so the attack will have to stop eventually.
Developers tried to tone down the price of transaction fee during the heavy fee of 2017, reason why they implemented segwit to solve the problem. It indeed solve the high tx fee of those time and I hope the developer will do the same today.
If these ordinals spam are keep unchecked, this might create a problem in the future.
If we're talking specifically about a network stress attack, then actually, it can stall price movement and additionally effect sentiment, as it temporarily highlights a flaw in usability and scalability for Bitcoin. It may be good for altchains that are more scalable, like ETH. It depends on the trajectory of the attack.
It will not only stall the price movement or affect the sentiment, it has more effect on the Bitcoin adoption and if this attack keep on going, many institutions that wanted to adopt Bitcoin may change their mind.