Put the download links back. This is anti-competetive behavior by Twitch.
On the minecraft modpack's pages there is no direct download link, and if you click on files tab, there still is no download link next to the current pack's version, or ANY of the pack's versions, you have to click on the current pack's file link AGAIN to get to a download URL or click specifically on the bottom right file link in the modpack page.
There should be a direct download link from the main modpack page, or a link to a downloads page labeled. Right now it seems it is deliberately buried and obfuscated to make it more difficult for people to find the direct downloads for other launchers, some may see this as an anti-competitive action by twitch in order to make third party launchers seem unavailable for these modpacks unless people know specifically which unlabeled links to click on, which may run afoul of certain laws.
Curseforge was the main modpack repository for minecraft users, ALL minecraft users, before Twitch came around, and now it seems like linux users are being forced off of a platform they have been a part of since the beginning. It seems like twitch is taking a strange stand, of both refusing to put the twitch launcher on linux, and also making it harder for linux users to find and use the modpacks that the community has made for MINECRAFT users and NOT JUST TWITCH USERS. Hell, even Microsoft might take some beef up with you trying to make it seem as if the packs created by their users for their games can only be installed through your launcher by taking over the largest community website for modpacks and severely obfuscating download links. Pretty sure if you are serving content that their creators have made, with Microsoft's intellectual property, and are serving it through your service, you have to also provide it unadulterated upfront with no hoops to jump through like even how to find the damn things. If there is a twitch install link, there should be a direct download link right next to it. I am around 99.9% sure Microsoft's lawyers will agree with this one, because I just realize you are making Microsoft's own intellectual property harder to use on THEIR OWN LAUNCHER, this is an anti-competetive act against the game's own creators.