The phrase "not so much as" can be replaced by a variety of synonyms, depending on the context. Some alternatives include "barely," "scarcely," "hardly," and "merely." Another option is to use a negation, such as "not even" or "not a bit." In some cases, the phrase "lack of" or "absence of" can also be used to convey a similar meaning. The choice of synonym will depend on the writer's style and the context of the sentence. Regardless, it's important to ensure that the chosen word accurately conveys the intended meaning and is appropriate for the context.