Fair warning: This is not a takedown. I am just explaining why to my particular use-case, Tiddlywiki is not a good fit anymore. In a way this is documentation of my Circle of Competence rather than limitation of Tiddlywiki. As a tool Tiddlywiki has persisted for 15+ years and earned praise from industry giants. So before dismissing it based on anyone's opinion, it would be only fair to give it a try.
On the other hand, I would ask the long-time Tiddlywiki users to stop and consider for a moment if Tiddlywiki is actually aiding expansion of their knowledge, or is it merely satisfying their urge to tinker with stuff. Also see Sunk Cost Fallacy.
For some years I have been noticing this pattern:
For this reason I am logging those reasons so I won't have to use my time and energy to rediscover them another couple of times.
Usually if a tool fails to clear essential criteria of its category (See Note taking Apps - Criteria), I do not bother to look into it any further. Here I am making an exception, at least to document the rest of issues.