Parentheses override precedence:
console.log((2 + 3) * 4) // 20 (addition first)
console.log(2 + 3 * 4) // 14 (multiplication first)
Even when not strictly needed, parentheses improve readability:
// Hard to parse
let result = a && b || c && d
// Clear intention
let result = (a && b) || (c && d)
Future readers (including yourself) will thank you for explicit grouping.