There is adequate strength in virtually all modern .45 Colt revolvers to come very close to the 1,000fps mark with a 255gr bullet in 6" or longer barrel. And thats where the old loading manuals max out, using Colt SAA as test firearm.
Even the old original blackpowder load was 900fps with the 255gr bullet.
Thats a significant edge on the .45 ACP whose specs originally called for a 230gr at 850fps +/- 30. The ACP can hit 1,000fps with light bullets, but not with the heavier ones like the .45 Colt.
In strong revolvers (Ruger Blackhawks and some others) the .45 Colt can be loaded to rival .44 mag performance.
Some of what you are missing is the history and nostalgia of the round. From 1873 until 1935, the .45 Colt was the most powerful handgun round commonly available. And even after the .357 arrived in 1935, the .45 Colt was still the big bore champ. The .44 Magnum took that title in the later 1950s, and keeps it still, even though there are more powerful rounds on the market today.
One thing the .45 Colt does is perform well in the field. Both in defensive shootings and in hunting, it works pretty well.
I've been shooting and loading the .45 Colt for 30 years, and my pet load pushes a 250gr SWC at just under 1100fps, doing everything I've ever needed a handgun round to do, without the punishing recoil of the .44 Mag.