Q: What issues do you experience so frequently that it would justify investing more money into it?
A: ... often ended up without the proper one when you needed it
That's precisely the issue GP solves by only carrying one type of cable, Thunderbolt. If you want to transfer data at top speed, render high resolution high refresh rate video, or charge at maximum wattage, TB4 handles it. One cable to rule them all, no surprises.
It rules them all, only if you are on a Mac yourself and have a Thunderbold cable.
If you are on anything different and want to hook up, say a Studio Display, you can't use USB-C (below 4) and that is not USB-IFs fault.
Besides that, what I meant was the connector standards mix before USB-C has become mandatory here, and I think you knew that. Other than that, all what you wrote is also determined by the devices connected, so this may be why most of the people out there don't even realize there might be a reason to buy Thunderbold.
Q: What issues do you experience so frequently that it would justify investing more money into it?
A: ... often ended up without the proper one when you needed it
That's precisely the issue GP solves by only carrying one type of cable, Thunderbolt. If you want to transfer data at top speed, render high resolution high refresh rate video, or charge at maximum wattage, TB4 handles it. One cable to rule them all, no surprises.