You are right, that's the best tool to use for the job!

However, as it usually happens with scripts, adding non-coreutils dependencies becomes an issue (now the script needs to check for existence, request users to install if missing, etc...) For this use case which is so well scoped, a single character removal seems enough but in general I totally agree with dos2unix as the better choice.

Note that dos2unix and unix2dos do what you expect when used as filters, but overwrite the specified file in place when given a file name. This is a footgun second only to one in pdftotext, arguably, which (unsurprisingly) refuses to work as a filter and (surprisingly) will silently create a matching .txt file when passed a single .pdf as an argument.

Why is that a footgun? If it just piped the output to stdout, then to convert a file, you then have to

    $ dos2unix file >x
    $ mv x file

In my mind, overwriting the file is the Right Thing.

The Right Thing would be to require an explicit -o <output filename> option to avoid modifying files without getting user's consent first.

Especially because the changes it makes are irreversible (e. g. when a text file has mixed unix/dos line endings).

Or flip (https://ccrma.stanford.edu/~craig/utility/flip/)! I've been carrying this thing around with me for years.