The custom profile I created has 71 mods. I exported it and uploaded it to my project on the curseforge website. All the mods show up under "Relations". After I did that I downloaded it from the "Browse Mods" section on the curse forge app. The file from the app only has 23 mods for some reason.
Ideally modpacks tell a launcher where to download the mods from, rather than actually include them in the pack. One benefit to that is mod authors get credit for downloads. But some mods are included inside modpacks (for example, if they're not available on CF but do allow inclusion in modpacks). Maybe that explains the 23 you see in the file.
The important thing is when you run the modpack, it downloads and launches with all 71 mods.