I no longer recommend anything. Use whatever you want to a launch a pack. I hope to bring my own branded but also easily rebrandable launcher out eventually. No eta and no guarantees and when that will arrive.
Koala Launcher (koalalauncher.com/download) is still faster than GDL (gdevs.io) but management style is the same: Totalitarian. It’s the view the current king or the highway and if you happen to be sponsored by someone other than his sponsor then your just a target for all kinds of attacks. Very unfriendly. I tried to make it friendly, I thought we had something but it became clear that was not going to be the case. In this regard GDL is much more friendlier. If you require an alternate 3rd party launcher that can make mod packs for both Fabric and Forge then you want GDL because it’s friendlier. But management style is the same. At least GDL doesn’t care who your sponsor is and they want needlessly attack you.
In Third place is Twitch launcher from twitch.tv/downloads. Second place because their dev release cycle is terribly slow, no Linux support, altho they do support Mac. Horribly slow pack downloads and just as slow pack launches. It does support launching the latest packs and mods.
MultiMC from multimc.org is great for launching Forge and Fabric. It can still install and load packs fast. It does have one major caveat in that it uses it’s custom API to download packs. Meaning that when others fail, this one will succeed. It also does not support building custom packs easily. Yes it supports drag and drop, but there is no custom catalog browsing of mods like you can do with the Twitch, CurseForge, GDL and Koala launchers.
There are other launchers out there and if you think I left out one that should be here, please double check that it browse and install Curse packs before recommending it in the comments below.