Sev·er·al [sev-er-uhl, sev-ruhl] adjective: “being more than two but fewer than many in number or kind: several ways of doing it.”
My reason? “Several” is too vague of a word. It’s also way too similar to numerical “seven,” which means using it can easily warp the meaning and context of a phrase.
Example: “I ate three slices of pizza” vs. “I ate several slices of pizza.” Which one of those sentences do you want to be saying to your personal trainer? Oppositely, what’s the threshold for where “several” turns into “many“? Example: “Several people attended the event” vs. “Two dozen people attended the event.”
Conclusion: “Several” is the word lazy people use instead of actually counting.