^^^^^^^
All of the projects you posted images of were from the go-go days of the 80's Dallas building boom. The first towers for each of the three projects were built but not the second. It would have been incredible if the three sets of twins had happened!
But there are some major differences between then and now.
The 80's Dallas building boom was heavily speculative in nature with many towers being built with no lead tenants. After several years of that occurring, it ultimately led to significant overbuilding of the overall office market in both Dallas and Houston.
When the double whammy of the simultaneous oil and gas and savings and loan downturns occurred the leasing dynamics for the office market changed for the worse.
And the three 80s' Dallas projects you mentioned were exclusively for office space.
Fast forward to today. The Dallas office market is not overbuilt. If anything, it is actually tightening to the point that there is beginning to be a scarcity of new state-of-the-art Class "A" or "AA" office space available. For new projects, signing a major lead tenant and/or securing significant pre-leasing is the norm today unlike the 80's.
Job and population growth in Dallas is among the greatest in the nation. Corporate relocations to the Dallas metro are occurring at a dizzying pace. Residential valuations are at all time highs. Retail is booming. Dallas is very diversified in its corporate ranks and the city and its metro are not overly reliant on one industry over another, further bolstering Dallas' stellar growth.
Another major factor is the Harwood Forum project is mixed use without relying solely on office.
Harwood Forum is "build to suit" residential, hotel, retail, and office. The opportunity is spread among several elements without a sole reliance on the office component.
From the renderings it suggests that the top sections of the two supertalls could possibly be hotel and/or residential.
One tower might house the hotel component and the other residential with the connecting skybridge providing common amenities to be shared between hotel guests and residential occupants. The middle and lower portions of each tower would probably be office with retail anchoring the first two or three floors.
The precise allocation between office space, hotel, residential, and retail is to still be shared by Harwood.
Another major factor is Harwood International, the developer, has an incredibly impressive track record in Dallas and has built a burgeoning and hugely successful series of office, residential and retail developments in the Uptown portion of Downtown Dallas over the last decade or longer. Over time Harwood has delivered and is delivering on every single project it has announced as part of its master plan.
There is no reason to believe they will not be as eminently successful with their "crown jewel" project of Harwood Forum as they have with their previous Downtown Dallas highrise projects to date.
Your point is well taken but the dynamics of today's commercial and residential market in Dallas are very different than during the 1980's and are underpinned by a highly diversified Dallas economy that is literally on fire.
Worse case scenario, if only one of the two supertalls of 1,080 feet in height were built, the Dallas skyline would certainly be better off for it!