For Obsidian, I use hierarchal tags (eg. #python/django/models) and the Omnisearch extension[1] for resurfacing and I don't have any complaints.

For tags, I use it much like a file navigator. In fact, it sits exactly where the files tree is in the default config. But, instead of files, its hierarchal tags.

1. https://github.com/scambier/obsidian-omnisearch

Recently, I had issues with Obsidian running out of memory and closing while in the foreground on my 6 GB iPhone, and the culprit turned out to be this add-on. Removing it reduced idle RAM usage on the desktop from ~1.1 GB to ~600 MB.

Just a warning for people like me who tend to collect nice-sounding extensions and then forget to actually use them.