You've clearly never worked on the development of such tech. It is very expensive to develop, and the development cost has to be amortised reasonably quickly to be worthwhile.
I've only watched one of those videos (produced by GCN) and while they explained why a bike could cost £10,000, they were also at pains to point out that for most cyclists, the benefits of a £10K bike over a £3K bike would be marginal at best, and unlikely to be worth it.
This is, of course, the important factor for most of us. The 105 groupset on my current road bike is as good or even better than the Dura-Ace groupset from 10 years ago.
I would be surpised if we don't see Di2 for 105 within the next 18 months or so, now that there are no mechanical versions of the latest Ultegra or Dura-Ace.