Hacktical C: practical hacker's guide to the C programming language

> Using a stricter language helps with reducing some classes of bugs, at the cost of reduced flexibility in expressing a solution and increased effort creating the software.

First of all, those languages do not "help" "reducing" some classes of bugs. They often entirely remove them.

Then, even assuming that any safe language with unsafe regions (Rust, C#, etc) would not give you comparable flexibility at a fraction of the risk... if your flexible, effortless solution contains entire classes of bugs, then there is no point in comparing "effort". You should at least take into account the effort in providing a software with a high confidence that those bugs are not there.

If the language has unsafe regions, it doesn't entirely remove classes of bugs, since they can still occur in unsafe regions.

(Predictable response: "But they can only occur in unsafe regions which you can grep for" and my response to that: "so?")

No matter whether you are using C for "freedom" or "flexibility" of "power", 95% of the time you only need that in a very small portion of your codebase. You almost definitely do _not_ need any of that in, say, the logic to parse CLI arguments or config files, which however is a prime example of a place where vulnerabilities are known to happen.