Especially if you don't necessarily have the trained mechanics who know how to check for signs of wear, or access to the records and maintenance manuals that tell you when you should be doing it.Or just run with worn bearings until failure.
Given how many Russians who had the means and skills ran from the country early on to avoid the drafts, and how it seems that the draft was pulling in anyone they could get their mitts on in certain areas regardless of occupation I wouldn't be surprised to learn that there is a shortage of qualified aircraft mechanics at a time when they probably need more in order to do more frequent checks as you can run past manufacturers "replacement" times on some parts if you're careful and do more regular checks, but it's a risk and does require much more frequent checking (manufacturers tend to be conservative in how long they expect bits to last in aircraft to allow a good margin of error but you get the edge cases that fail early or not long after that limit).