EDIT to add: These are my opinions obviously. Your opinion may be different. I have no connection to anyone in the modded minecraft world.
I've always said v1.7.10 modpacks would be the high water mark for modded minecraft. It remains my opinion today. V1.7.10 days was when FTB was at its peak (FTB Infinity Evolved) and when the mod selection was the best (we still had Eloraam's Redpower mod, etc).
yeah I know others took over redpower and made it into Project Red which still exists today, but its never been the same since Eloraam left the scene. And she wasn't alone of course. Who remembers Agrarian Skies modpack, perhaps the first real "outside the box" modpack? The developer Jaded Cat hasn't been heard from since Agrarian Skies 2.
Their legacies live on, but Agrarian Skies isn't even in the FTB Launcher anymore, most likely there was a personality falling out or something. It's all been downhill for a few years now, but nobody really seems to have noticed.
Twitch is an utter mess, there's a million (literally) modpacks posted each day and 99% of them are exactly the same thing, just different mod selection. There's no real search function on Twitch, there's no pack reviews or any way to tell if it's a pack worth playing or not.
Oh well, sure has been a fun ride, and yeah I know it's not over yet and there are still new modpacks coming out all the time... but it won't ever be like it was back in the glory days of FTB. There's just no money in it for them, there's no great drive or desire to keep it all going.