13.6.1 is to specifically address abnormally large Other (and an unrelated green tinge problem on the screen of some phones). But Other is real data—>What is "Other" and What Can I Do About It? | Apple Support Communities. It’s only when there is storage corruption that Other becomes a problem. The current problem has nothing to do with 2 years ago. And reddit is not the final word on anything, and not a reliable source. For much longer than 2 years occasionally an iPhone would suddenly show a very large Other. In the past this was caused by an interrupted sync. During a sync content to be moved between iOS and iTunes was “staged” in storage (in Other), then in the final step of sync it was moved to the “sandbox” of the applications that owned the data. If the sync was interrupted before that final step the staged data would remain in Other.
The current problem has similar symptoms, but a totally different cause. It appears that it arose in 13.5.1 (or maybe 13.6), based on the fact that there was an order of magnitude increase in the reports of the problem in this forum and other sites. And it only happened to users who were already running out of available storage. A user would delete content, but not recover any storage. And Other would increase by the size of the content deleted. The reasonable assumption is that the space occupied by the deleted content was not being freed. This is the specific problem that 13.6.1 addresses.
If someone has a phone with plenty of storage they probably won’t even notice the size of Other, and they are also unlikely to delete large amounts of content, so even if Other grows larger as stuff is deleted they probably won’t notice unless they are actively looking for it. So that’s why the help article specifically refers to “when available storage is low”. I updated a family member’s iPhone 8 to 13.6.1 The phone was not short of storage, and did not have an especially large Other category, but Other went from 7.2 GB to 5.2 GB after the update. (My phone is not on a version affected by this problem).
The previous way of fixing it also works: Back up the phone, then restore the backup. But that doesn’t prevent it from recurring. I’m hoping that 13.6.1 fixes that also. Early reports are that it fixes the current problem by cleaning up Other. And several users who have access to the level 6 and above forum noted that it reduced their Other storage, but didn’t do it all at once. They could watch it go down over a period of several hours.