I have the feeling that people does not follow correctly their merge request during the review process.
For example most of the MR, I have reviewed, stays with unresolved threads for a very long period (if it is not forever).
I just want to remind that I wrote a JS script to see in the list of merge request, the unresolved threads for each MR. I encourage everybody who submit a MR to install this script in order to see why your MR is still not merged.
This does not solve anything. For example here is a MR which I’m waiting for ages for some remarks and despite I’m having the MR assigned I can not resolve unless some clarifications are done. If you do not review it because it has some unresolved threads and I’m waiting for your review, we will never solve such issue.
This is another example of MR that its waiting for feedback and its waiting to be resolved.
There is also the case of some MR that are never reviewed no mather having unresolved threads. See for example:
I’m not there to solve all problems.
No, I’m here to solve all problems. I’m the solution Institution. Hahah. 
Joke aside,I’m not asking you to solve all problems just to clarify a remark that you made and I did not understand what do you mean. The code is working and the MR is not merged because some comment asking “duplicated code” that I can not understand nor have a better way to solve. I already added a two comments requesting for clarifictation but unless this is not clarified the merge request can not be followed…
This twitter thread (sorry but in Spanish) for me describes our current situation with MR.