Obsidian vaults can be converted into formats that work with competing PKM tools. I swapped back and forth between Obsidian and an open source tool based on Visual Studio Code for a while.
"But my workflow is portable!" is really not a good response, when a workflow like OP's, or even one that depends on a few key plugins, becomes very much not portable. The more you buy into the ecosystem, the less portable your workflow will be. "Don't buy into the ecosystem" is not a reasonable take at all because that's the entire point of Obsidian over competition, the (mostly open-source) ecosystem that they have with the first-mover advantage.
What will you do if they stop developing? Start maintaining the code yourself? Wait for others? Very few open source projects thrived after original author lost interest.
The most basic type of links, links to other notes, will generally work fine yes. But what about links to headings? Links to blocks? Links to attachments? Embedded blocks? Embedded files? The more you've used Obsidian's features, the more stuff will break.
Searching by tags is trivial. What about searching by properties? By done/undone status? By note attributes, by tasks, by attachments, by block-level searches? What about filters?
The simplest use-case being, if I simply want to view the list of all undone tasks across a set of notes on a separate app, sorted by priority, as I can now on Obsidian? Not trivially possible, as far as I know.
Reminders and any calendar-like functionality are definitely not carried over across apps, either.
Like I keep saying, if you limit your functionality to just markdown basics, it'll work fine. Start using the exclusive features of the app or even just the tasks plugin and it's no longer so simple. Something like the Kanban plugin is just impossible.