The Biggest Modpack

It Took 5 minute for it download, Then when it download i wait another 5 minutes nothing happens.

As I'm sure comes as a surprise to no one this is certainly not "the biggest modpack," however, it still falls into the many pitfalls of giant kitchen sink packs.
You have your standard annoyances, being spammed with books and inventory junk when you spawn in, your chat is filled with warnings and messages from various mods, redundant ores, loot tables clashing and filling up chests incredibly quickly, and overlapping hud elements in the GUI. Though I've seen worse, it's not pleasant.
However, what really bothers me is the lack of QOL features like controlling or a mods menu button, these are essentials in almost any modpack, much less a kitchen sink with the goal of high mod counts.

Gameplay wise there really isn't much to talk about, it took me all of 20 minutes to search for jei, find the recipes and emc values of projectE are unaltered, get a transmutation table, and of course, from there progression and balance are a non-factor for many mods.
Of course, if you simply want to use kitchen sinks like this to experience what the modded community has to offer, doing so through a pack with lots of mods that lets you become op through projectE and ae2 and the likes in my opinion is actually a great way of doing so, and I don't judge you for wanting to play this way.
However, I don't think this pack actually lets you do that very well, mods like projectE and ae2 are typically expected to come with a host of add-ons that allow them to be compatible with other mods, and generally make your life easier which are not present in this pack, something that hurts what I view as the one good purpose for "just throw it all in there" style kitchen sink packs with little to no customization.

On that front, as best as I can tell almost every mod is in its default state when you boot up your world, while CraftTweaker is present in the pack I couldn't find any recipe changes and the "scripts" folder looks to be empty.

The one goal, namesake feature, and stated purpose of this pack is its size, while the title "The Biggest Modpack" is transparently hyperbolic, where does it really stack up?
The version I played had 302 mods (according to Curseforge's Related Projects tab)
This is decent and it is more than the stated 250+ in its excerpt, but I personally would only barely consider it a big pack.

Here are some bigger packs that I would recommend instead, and how many mods the latest version has:
The Enigmatica Series - (E6) 367
The All The Mods Series - (ATM9) 422
Monumental Experience - 610
BeanPack: Regurgitated - 619
Starpack Titan - 650
The TNP: Limitless series - (TNP 7) 719
Mystics Monstrosity* - 1,091

• I've not played this pack myself

I love big kitchen sinks, I think packs with lots of mods, even with little to no customization can be a great way to learn about different mods and find out which ones you like and dislike while keeping the core sandbox feeling of Minecraft alive. However, when done poorly the result can be a buggy low-effort mess that runs the risk of making your experience worse than if you just played a small pack with the few mods you like.