Deprecated stuff cleanup

It is very important not to just mark things as deprecated but also clean them up. Not necessary to do this right away as a high priority job, but at least create tasks for the pieces to clean up and work on them every sprint or at least periodically to make it happen eventually.

If this does not happen - it is going to be one more thing to maintain as it will be reused and copy-pasted not a single time just because new joiner or people who are not very familiar with the context will be using these solutions just because “this is how I found it being implemented in X”.