This is impossible to happen.

Security flaws are discovered almost every day (now that they are automating it with AI there are a ton of reports), pretending the manufacturer releases an update in 1 day is nonsense.

Just building the code alone it would take a lot of time, and of course you have to test it at least a bit before giving it out to the end users, you can't pretend to rollout on a global scale a nightly build without first at least some level of QA risking bricking user devices.

And you have to consider that phone manufacturer doesn't work h24 and 7/7 of course to give out patches.

I think that we are fortunate if the whole process takes less than a month, not a day.