Most expansion joints in the Houston area WERE 1x4 redwood, pressure treated, or perhaps cedar. Anything 7-10 years old is pretty much GONE. The filler pictured above replaces 1x4; does not need a sawcut, or anything fancy.
Having installed this type, and caulk, I can say that for a DIY weekend project, the guy installing this strip will be kickin' back watching football while the guy caulking will still be on his knees squeezing his gun
30+ linear ft per minute to install is not hard to do with the rubber filler.