but it is getting a bit ridiculous how many serious and lingering vulnerabilities are found.
You have to be new to software, nothing in the world is 100% safe even Apple products. Windows, Linux, third-party applications, operating systems for mobile phones have shortcomings. Every time an update is released, there is the potential for shortcomings because these are not simple programs.
Apple really needs to recognize its bug-bounty game and start paying real money for people to find those gaps.