Hi,
sorry for the late response! The StopModReposts team is currently working on a mod that authors can integrate into their mods and modpacks (more about the mod here: https://stopmodreposts.org/dl/splashscreenmod.html). The "mod" basically shows you a popup on the first game start, which tells you about the campaign and where to download mods.
I personally agree that the Forge Developers are NOT responsible/liable to show users where to download, but some fake websites like files.minecraftforge.com should be taken down via domain abuse if further illegal activities take place on the site (currently, weird redirects which aren't illegal). We would be happy to further discuss this topic on the official StopModReposts Discord Server which can be found here: https://stopmodreposts.org/.
Sorry for my English sometimes. I'm German! ?
Kind Regards,
Paul (MECTAG/berrysauce) @ StopModReposts