From what I’ve seen on this forum (and you can check as well; look for offloading issues especially), iCloud – despite being an integral part of the iOS/iPadOS ecosystem – is a very iffy solution, which Obsidian only provides because the OS makes it possible.
About a year ago, I ditched iCloud completely. I had Windows at the other end, granted.
See also a rant-ish opinion that hits oh-so-close to the mark:
As for the plugins taking too long to load, I tried different ways to ease on startup time, but your issue sounds different.