Overall, I agree that the promise of tech in education never manifested, or at least hasn't yet, and the last decade was full of half-baked or poorly conceived ideas. But I'm worried there's some baby in that bathwater...
I started my career in K-12 education, first in the classroom, then as an administrator, and thanks to a coding bootcamp, am happily pursuing another career as a software developer. I have plenty of friends who've done the same. Will it be a long-lasting model? I don't know, some are clearly already out of business (the one I did, Hack Reactor, is still going though). But it may be the first wave of upending having to spend six figures on accreditation / skill acquisition.
And while a lot of the flipped / personalized tools never panned out specifically, a lot of the concepts were helpful in bringing in new structures to instruction. The ideas helped us move away from simply "I do, we do, you do" lessons to units where students could get some material up front and then do more exploratory or self guided lessons, and teachers could work with individual students who needed attention.
Education needs innovation. Instructionally, the major changes won't come from software but from restructuring how school operates at different grade levels. Given the different needs of 7th graders from 3rd graders, it's interesting that their days are still structured so similarly, not to mention that we're still not really developing skills that are useful for the kinds of jobs that exist today.
That said, there is a place where there's a desperate need for high quality software in education: operations. Follow a school office manager for a day and you'll see exactly what I mean. The number of systems that are still either paper-based or involve manual processes that can quickly be automated are incredible. As with any public enterprise, there are lots of reasons that these systems haven't been updated, but streamlining operations for schools will actually make much bigger impacts for student outcomes than almost all the edtech software out there.