Requirements for large projects are always more than technical. The killer feature of proprietary software is the power of the purse.
Often, a reason large organizations buy proprietary software is because of the power structure created when you have a legally binding contract with the sole maintainer of the project.
The #1 customer of a proprietary product has quite a bit of power to influence and shape how the vendor spends their development cycles. For FOSS, you are often cooperating with (or at least partially reliant on) people who have no financial incentive to favor your priorities.
Often, a reason large organizations buy proprietary software is because of the power structure created when you have a legally binding contract with the sole maintainer of the project.
The #1 customer of a proprietary product has quite a bit of power to influence and shape how the vendor spends their development cycles. For FOSS, you are often cooperating with (or at least partially reliant on) people who have no financial incentive to favor your priorities.