More caulk than I can handle

Very new to any house DIY. This bathroom hasn’t been touched in decades and we are doing our best to give it a glow up. As you can see, the caulk is ancient. I scraped off the stuff from the bottom seam, and the video is what I’m looking at. That’s a big gap. Broken pieces of stuff are in there. Seems like a lot of space to caulk. I saw another post here where someone put a quarter round in a space like that and everyone was pretty horrified at that, which I get. But what am I supposed to do with this situation? Please help!