There is no way to put this gently, Tiddlywiki UI is outdated. Yes, beauty is in the eyes of beholder, I am being superficial yada yada. Despite having immense potential and ease with which Tiddlywiki could modify its UI, it decided to stay with the 90s. Biggest visible changes to UI in the core has been introduction of menubar which is an eyesore. Well intentioned developers had offered to help out for free, only to be never heard from again, presumably due to lack of input or interest from the community.
Tiddlywiki had been plagued by lack of a centralized store for community plugins till last year. It finally came up with a very creative solution which solves categorization, quality control and use of human resources of community in a single swoop. However the response from community has been lukewarm at best. A full year after launch, it has 13 contributors listed.
Basic features like search-and-replace across notes should not require a deep dive into the documentation and rolling out your own buttons.
While tiddlywiki has a third party android app, the user experience is not at all comparable to Markor or Producthunt Golden Kitty Award Winner - Obsidian.