This is exactly why on most phones you can turn this feature off, which is also good to know.

If you are really really curious, you can find a phlebotomist that is game and use your own blood. This is the most ethical way to get some cooking blood and it can be done. (For proof see article)

https://www.vice.com/en/article/i-made-meringues-out-of-my-own-blood-and-ate-them/

You don’t even need the movies to have some dystopian implant horror. Second sigh used to produce a sight restoring implant. After some financial trouble they stopped manufacturing and support for one of their products. Leaving recipients of the implant sightless in the case the hardware breaks.

https://www.bbc.com/news/technology-60416058