Some plugins are Another Quick Switcher, File Explorer++, Force note view mode, Remember cursor position, and Open in New Tab. These plugins mostly chance existing functionality to work better how I would expect them to or add some QOL features. Obviously I don't expect Obsidian to implement massive features like Dataview, Kanban, Projects, Calendars, etc.
One of my biggest complaints though is Obsidian's tab management. Notes are always opened in whatever tab I am currently in, even if the note is already open in another tab. I know that I can just hold shift or ctrl to do a new tab but I forget to do that all the time and would just love a toggle to always open notes in a new tab, or swap to an existing tab that note is already open in.
The default quick switcher I feel is also very bare bones. I can't search by tags for example.
I would also love it if obsidian had native markdown table support similar to how the advanced tables plugin works. I know I can just use that plugin but it does not work in live preview edit mode which is what I prefer to use. I don't know if that's an Obsidian issue or a plugin issue.
I'd also like to see tree style tabs or just vertical tabs in general similar to vscode's open editors feature. I tend of have many tabs open and am constantly switching around.
Overall though maybe I'm just using Obsidian wrong or its just not for me, but out of all the note taking apps/markdown editors I've used, Obsidian is the closest to perfect that I've seen.
EDIT: I should add as well, I do appreciate that Obsidian allows for plugins and custom CSS. I'd rather be able to change the things that I don't like rather than be locked into the default functionality. However with some of these plugins being implemented in "hacky" ways as their description says while also not being updated in quite some time, I do wonder how much longer they will continue to work before an update breaks them permanently.