I don’t fly Southwest, but I’m curious if they take surfboards, which would often exceed that length limit except for the shortest boards.
By comparison, Delta’s limit it 115 linear inches.
https://www.delta.com/us/en/baggage/special-items/sporting-equipment
I haven’t looked at other airlines but I’m sure Southwest is on the low end.
Also, side note: some of them allow more weight if you’re in an upgraded class. Worth reading the fine print so they don’t nickel and dime you.