Here is a pic showing the overhead bins in a 737-800. The commercial aviation industry has changed and is promoting carry-on luggage and is charging an arm and a leg for checked luggage. This 737-800 easily held my traditional carry-on bag, even when placed sideways. A couple of downsides are longer loading and unloading times and that crazy phenominum where people are taking their luggage with them during emergency evacuations. Oh yeah, flights in Canada still have mask rules. Let’s ignore that one.