These things are fairly orthogonal. There are interesting problems, there's interesting tech. Sometimes interesting problems require interesting tech to solve, but not usually. Often boring problems are best-solved with interesting tech, but they can optionally be solved with boring tech. In my experience, solving interesting problems with boring tech is far more frustrating and unfulfilling than solving boring problems with interesting tech. But again, they're pretty orthogonal.
There are a tremendous number of jobs using interesting tech to solve boring problems. This is really the bread-and-butter of most tech careers. You might be selling widgets or building another social network or something that is mind-numbingly boring and unfulfilling, but if you're into the tech, you might still enjoy your day-to-day. That's certainly been the bulk of my career. I've also worked on solving interesting problems using boring tech, and while it was nice to see the results at the end, the path leading there wasn't as fun.
If you're lucky enough to land both, that's great. I've worked on interesting problems with both interesting and boring tech (NASA projects), except it didn't pay well. I've worked on boring problems with interesting tech (fintech) and that both paid well and was actually more challenging and more fun. And I've worked on a whole lot of boring problems with boring tech (countless ecommerce web projects).
At the end of the day, if I can't have both, interesting tech is probably more important to me, because that's what I spend almost all my time dealing with, and I'm still a hacker at heart and appreciate the tech in itself. It does leave me feeling, most of the time, like my work has no meaning, but I can find meaning in other endeavors. There aren't enough interesting problems that also pay the bills to go 'round, so most of the time I just want my day-to-day to be engaging.