So I (and everyone around me) don't take them seriously. We take the actual deadlines seriously. The only thing OKRs seem to do is provide direction to the higher ups about what my team is up to.
It was not a good use of software developer salaries. An initiative to at least start collecting the data we needed so it might be useful in 2-3 years could have been, but some OKRized version of "start collecting data to use in OKRs 12 quarters from now" wasn't something anyone would get behind and was pretty much impossible to tie to the higher-level OKRs that were being set.
Whole thing was a game to find something easy to measure that could be made to look useful, whether it was or not. It wasn't some huge disaster or anything and I can see how maybe in exactly the right organization it might work, but there's no way it was the right place for that company to spend their money.