Igor, I think you make it sound a little too easy. To tame the modal region, I had to add a number of bass traps in addition to room equalization. And trying to find and eliminate spectral reflections was not exactly easy--it took a lot of measuring and experimenting.
I know you aim for perfection in everything, I do too. And sure, with such goal it is not as easy and requires measurement tools, much of knowledge, experience and a lot of experimentation. But for most people it is just the easiest and least expensive way to get very good sound just by finding the best position for sub acoustically (with least dips/nulls, often this is the most complicated step), and then just bring some acoustic panels to tame the first reflections, SBIR/LBIR and let good room correction system such as XT32 do the rest. By my experience the most complicated problem that cannot be solved by EQ is the positioning of speakers and listener. This is what gives the biggest improvement. And this is definitely not easy. But once done this makes everything else significantly easier. It is definitely a lot easier to achieve perfection or get close to it with using both tools - EQ and treatments together, than with just one of them. So, when I tell easy I mean it is in comparison with alternatives.