I'm also bothered by very detailed QR codes. Milk cartons in my country had a QR-code for their website. It would be a ~10 letter url, maybe with a short path. But for some reason, the QR code was extremely detailed, as if it contained several kilobytes of data. I'm not sure if there were a large number of tracking-related parameters in the url, but it was very obviously unreasonably large.
Strongly agree on this one. Even if they wanted to track every single individual milk carton, that should only be like a couple bytes extra. Overly complex QR codes look ugly and are harder to scan
The complexity is likely a product of redundancy and error correction in the QR code rather than making it unique. You begin to run into issues with camera resolution and whatnot, but in theory those codes are likely more reliable.
You don't have to use a third-party short URL service. It can be hosted on your own site.
A lot of people are already using a third-party short URL service like qrco.de because they don't realise you don't actually need a service like that to make a QR code.
Regardless, why bother running or using a short URL service? QR codes can easily hold a full URL and more, and QR codes are not (nor are they meant to be) human readable, so what's the benefit?