I think you are mistaken, the problem is that there is not enough network capacity. Increasing the networks capacity solves the problem of congestion now. You need to think about this more long term, now is not the time to restrict the throughput of the network. If we have twice the network throughput it will be twice as expensive with the same fees to attack the network. This property increases as we increase the blocksize. Bitcoin will not be able to compete with the alternative cryptocurrencies when they can just increase the blocksize, this was always the intention with the original design of Bitcoin as well. In the long term we might have more expensive fees but I think that should be up to the free market to decide, not enforced through an economic policy tool like the blocksize limit. With an increased blocksize over the long term it will be much more expensive to attack the network in this way. Making Bitcoin more unreliable and expensive will simply just lead to its obsoletion, we can already see how Ethereum is rising in response to this crisis. Most altcoins already have a TPS in the hundreds, the 3-7 TPS of Bitcoin is just a bad joke there is no chance that Bitcoin will remain the dominant cryptocurrency if that remains the case.
Unfortunately even a 32MB blocksize (or even larger) can't be the answer. Spammers could just load 'em up with crap low/zero fee transactions.
How much legit traffic is there right now?
In that case miners could put the spam into blocks making them pay for it, zero fee transactions will just get dropped. While also avoiding any confirmation dellays in the proccess. In the example that you mention, with a standard low transaction fee of 0.0001. It would cost approximately 6.4 Bitcoins per block to attack the network. At the current Bitcoin price it would cost approximately four hundred thousand dollars per day to attack the Bitcoin network with a thirty megabyte blocksize limit. I would argue that this is a much better defense against a spam attack compared to restricting the blocksize, while very importantly not sacrificing the utility of Bitcoin.
Bitcoin is a permisionless network, I do not think there even is such a thing as spam unless you can prove the malicious intentions of the spammers, which is sometimes the case. I do think that what we are seeing now is the network simply reaching capacity, which is why its capacity must be increased or Bitcoin risks being out competed and obsolesced by alternative cryptocurrencies and fiat.