Are standalone SaaS apps dying in favor of browser extensions and ecosystem plugins?

I've noticed a massive shift lately where people would rather use a lightweight Chrome extension or a Slack bot than open a full web app for a simple task. Building your own native features takes months of design and engineering work, but users might still churn because your tool feels like a silo. Figuring out when a workflow gap needs a deep integration instead of a simple UI tweak is honestly one of the hardest product calls to make.

If you've been through this what was the biggest warning sign that told you it was time to build for other platforms?