Never use viewport-relative units (like vw) for text sizing, it is not a best practice for accessibility (part of the reason it's not in the examples here).
Modern browsers handle zoom just fine, regardless of units. We use rem in case a user has set their own preferred base text size (the same reason we don't use viewport-relative units).
Modern browsers handle zoom just fine, regardless of units. We use rem in case a user has set their own preferred base text size (the same reason we don't use viewport-relative units).