Weird CICD practices at new job?

I recently joined a very mature project and just learned about their production pipeline.

Essentially everything gets merged into the master branch. Only your unit tests are run during your PR. Integration and end-to-end testing are skipped.

The master branch gets deployed into staging every few hours, while the end-to-end tests are running on staging. If tests pass, staging gets pushed to production.

This means that if everything goes well, production gets updated every few hours 24/7. However that also means PRs are not fully tested and can break staging, thus halting production updates.

I'm not trying to criticize their methods, the company if full of amazing engineers and does quite well. I'm just very surprised and honestly afraid of breaking prod (I'm used to smaller projects where the full test suite runs on every PR). Is this a common practice? Any tips on how not to destroy staging/prod ?...

Edit: title was certainly misleading. I am not criticizing the company as they clearly do well. Group testing multiple PRs into staging, thus blocking release if any single PR fails: that's new and daunting to me. But everybody here seems to find it awesome, I'm sure I'll get used to it.