I dont disagree that Topic Tags CAN / COULD be a valuable thing
BUT when 99% of memories submitters DONT even input topic tags
then the value of such is not very great . . . .
RATHER use AI and other technologies to SUGGEST or AUTO CREATE topic tags

If I link a family bible record to Mary Smith
The system should be smart enough to add / suggest - topic tags of Family Bible
and MARY SMITH

Many topic tags can be extracted from a description and title as well as the person the item is linked to.

simply saying "topic tags are a good thing"
when hardly anyone creates them - just doesnt cut it.
And just encouraging people to use topic tags - just wont cut it either - - no matter what you say - a huge percentage of people will still not go thru the effort to create them manually

if you continue with topic tags - then make the system smart enough to suggest many of them automatically - when the item is created.