A long time ago, I was working with a startup that made a BLE-based consumer device. It had a mobile app that you used to exchange data and change settings.
The startup didn't make the hardware. They used an overseas supplier who made the core, and wrote the firmware. They relied on another supplier that provided the BLE module. A third group did the firnware that ran on that, plus bridged to the main board. And yet another did the inputs, display panel, and drivers.
None of the companies trusted that the other wouldn't steal their IP (since they, themselves had no problem including 3rd party libraries without credit). Trying to fix a bug entailed talking to A, getting info, passing it on to B, who would guess at the problem, then getting C to implement it without access to A or B parts, and doing final testing with D.
The simplest change took weeks and sometimes months. The easiest solution would have been to hire people in-house and do it yourself, but the startup was afraid of ballooning headcount and the cost.
It finally shipped a year late and way over budget, but all their future product improvement plans were put on hold. They went out of business a couple years ago.
I totally empathize with Panic. It's hard to do this yourself unless you commit to hiring the right people and keeping them busy with a raft of new projects.