Does Wi-Fi 6E make a big difference in dense areas?

Yes, but only if you’re using a 6 GHz network with a Wi-Fi 6E router and you’re close enough. The 6 GHz band is new and mostly empty, so you get less interference and more channels — great for crowded apartments or conference halls. The MacBook Air handles it well, but the signal doesn’t penetrate walls as well as 5 GHz.