Dear Sechel,
Look up your source’s sources. You are not reading it right. It is not a halacha sefer.
Ther Litvaks shaved in Europe before Rav Moshe came around. For those that actually learn the sugyos, it is simple. Though some are not comfortable because the result is the same as the razor.
For certain reasons that we won’t get into, almost none of the poskim from Europe published on the topic.