No, I think the parent has the right of it. I'm not equipped to analyse Tesla as well as I am for SpaceX, but I can say that the latter was
not a bet on uncertain future technologies. While they have certainly deployed some pretty nifty technologies along the way, those have been in service of comparatively marginal improvements (improving payload margins). The more fundamental innovations in cost-reduction and reusability have
not been particularly technology-driven, and could have been accomplished in the 1980s if not earlier.[1]
For example: putting most of your operations under the same roof, with engineering right next to manufacturing, and employing common fuel, engines, and tank manufacturing techniques for all stages. Nothing about that was at all technologically risky -- but SpaceX was able to get maybe the first 50% of its cost-savings simply by doing that.
What prevented this from happening in the past wasn't technology, but a Nash equilibrium, as the parent rightly says. Existing rocket makers couldn't put all their operations in one place because that would mean eliminating jobs in scores of congressional districts while only creating jobs in one or two. Would make too many enemies in congress that way, and because the government is the primary customer, you'd never get another launch contract again. And there isn't enough private demand demand to make up the difference, because the cost of spaceflight is so high. The cost of spaceflight is too high, because rocket R&D and manufacturing is split up over hundreds of facilities in dozens of states, creating insane inefficiencies. (Back in the 90s, one fellow I met who worked on the Atlas program told me that they had 7 managers for every engineer). And you can't reduce those inefficiencies because that would mean eliminating jobs in scores of congressional districts, etc...
See, the logic of the industry was self-supporting and entirely circular. Elon Musk's genius was in simply breaking this logic, and aiming for a new equilibrium where rockets are cheap, there's a strong market for private launch services, and contracts aren't awarded on the basis of how many jobs they'll create. Cool technology wasn't the key to this.
Like I say, I'm less well-equipped to analyze Tesla, but I can already detect a similar pattern of equilibrium-disrupting innovation with how he's approaching The Boring Company.
1: The Delta Clipper (https://en.wikipedia.org/wiki/McDonnell_Douglas_DC-X) demonstrated all the critical tech that you need for a reusable Falcon 9, in the early 1990s. It was preceded by some classified programs that accomplished broadly similar feats as much as a decade earlier.