Tbf vanilla Skyrim had more than 100 hours of content, just not story driven. Back when it came out I played well over that on PS3 in a single save with no mods. I explored every dragon shrine and collected all the priest masks in that playthrough. I did loot every damm vase though and inventory mgmt was slow. I got crafting up to 100 naturally, etc. Then made new characters eventually. Im sure I spent more than 300 hours over the years before I went to PC and installed mods