The @mention collaboration feature, that can be used on Notes in the timeline, is in the pipeline for depreciation.

I logged a support ticket, explaining that the @mention feature does not work in the "New Look". Apparently due to the "modern text editor control in Notes".

Now, instead of fixing the issue for the "New Look", I received word that the feature is to be deprecated altogether. Why? It seems so trivial these days to have a @mention option. We used it all the time.

Instead, time should be invested to make this feature more intuitive. Allow it to be used on more entities (like "competitor") and make work of better notifications for these @mentions (like already mentioned in other ideas on this forum). But certainly not remove it.