I disagree. All sorts of things use filters to solve problems. From my point of view (an end user), I don't have to configure or manage my spam filters, I just end up not getting spam. I used to, it sucked. But now I don't and it's the same email address. I consider the problem solved.
Right. Just like the internal combustion engine is a kludge because you need to change the air filters in your car. A real solution would be an engine that didn't need filters, anything else is just a clunky hack.
An IC engine would run just fine for quite a long while with no air or oil filters. The filters are there to prolong its lifespan, but are not strictly necessary for basic operation.
How long would your email be usable if you turned off your spam filters?
Engine aire filters are also preventing the INGRESS of foreign contaminants. Most spam filters are much closer to the receiver than the sender. So the spam email volume still moves through many servers, routers and networks before it is finally filtered out and stopped.
I don't think your analogy holds up at all.
A solution would be one which prevents the sending of the spam in the first place, or an auto-rejection mechanism that was 100% passive and 100% accurate.
Spam is merely a problem that is manageable with some ultimately clunky tools.