I don't see the assumption anywhere that the filter question is a separate step from anyone else here. Even if you mean a phone screen, then the easy filter question is only one of the very first questions of that phone screen, the rest will be more substantive.
So let's continue with the filter question not being a dedicated extra step (really, I don't think anybody assumed so):
> Why would you bother with those last 5 companies? Just go for the companies that respect your resume enough to bring you in for a real interview.
Because presumably I want to work at any of these companies. If the thing that's stopping me from applying to them is answering a trivial question, either my desire was not strong at all to begin with, or there is something seriously wrong with me.
Even if this is about the phone screen and not a filter question per se, I'm still not sure I really like the idea of omitting phone screens for more senior positions because you might lose on "better" candidates. For such a senior engineer, a phone screen should basically be a formality, and actually a chance for themselves to dip their toe in. Not just in seeing what kind of technical areas they come up with, but also an opportunity to ask preliminary questions about the company and the position in general. If that is off-putting enough to not consider applying or stop the process, then, again, the desire to work there could either have not been that strong, or the other reason.