Part of the issue is exactly what you just mentioned: There are a lot of different standards with varying degrees of compatibility, and none of them are visibly different from one another. There isn’t a good way to immediately identify which cables are “good” and which will just outright refuse to charge your devices. So some of my USB-C cables will charge low power devices, but not bigger things like a laptop or iPad.
Meanwhile, the lightning charger was really really good at enforcing uniformity across different cables. Because you knew you could plug any lighting cable into any lightning port, and it would charge just fine. Yes, this inevitably caused issues with speed as tech progressed and Apple refused to upgrade to new standards. But that refusal also helped them maintain uniformity. Apple also shifted away from hardline data transfers years ago; 99.9% of iPhone users will have iCloud backups happen automatically via wifi, and iCloud means you’re not doing full phone backups every time. You only do the initial backup, then it simply pushes daily changes as you go whenever you connect to wifi. So the actual amount of data that gets transferred is relatively low with day-to-day usage, and it doesn’t eat into your limited call phone data plan. The regular user rarely (if ever) needs to transfer anything via the lightning port, because wireless sync takes care of things as long as they’re on wifi.
The rapid development of USB-C has been great for the tech. But it also means that (as someone who has an iPhone and has very little need for USB-C cables) I’ve bought more USB-C cables in the past two or three years than I have lightning cables. Because my five year old lightning cables are still working fine, while all of my USB-C cables from before the pandemic had to be replaced; Not because they were broken, but simply because newer devices would refuse to charge with them.