Do NPC spellcasters need a component pouch or an arcane focus?

Question

By D&D 5e RAW, is it possible for the BBEG (or any NPC) to cast spells without needing material components? Alternatively, is there any powerful magic item (e.g. a ring or pendant) in the rulebooks that can allow its wielder to cast spells without needing a component pouch or an arcane focus?

In other words, is there any way I can repeal the following rule?

Casting some spells requires particular objects, specified in parentheses in the component entry. A character can use a component pouch or a spellcasting focus (found in chapter 5) in place of the components specified for a spell. ... A spellcaster must have a hand free to access a spell's material components—or to hold a spellcasting focus—but it can be the same hand that he or she uses to perform somatic components. (PHB p. 203)

Answer 1

Innate Spellcasting

A Drow Matron Mother's Innate Spellcasting feature mentions

The drow's innate spellcasting ability is Charisma (spell save DC 20). She can innately cast the following spells, requiring no material components:

Ruby of the War Mage

A RotWM can be imbedded in a weapon to allow its user to wield it as an Arcane Focus. Combined with the Warcaster feat, it's a good combo.

Homebrew monsters

You can give the BBEG a custom ability stating that he does not require components to cast spells, or a magical item to cast the spells through (like a Staff of Fire)

NPCs don't need to follow PC rules

You don't need to go into specifics. You can just handwave it, and this BBEG can do whatever you want him to do. You're the DM, as long as the encounter is fun for the players, you don't need to drown yourself in more rules that slow things down.

Build something that works for your table.

Answer 2

I would suggest that you not repeal the rule, unless the way that you do so is also possibly available to the players.

It is important that the players feel that their characters live and adventure in a fair world. If you have too many rules that apply differently to the characters than they do to the NPCs, it feels unbelievable, and unfair.

It is my practice, and long has been (more than 40 years) that the NPCs and monsters of my world DO have to abide by all of the same rules as the PCs do. Not only is it more fair, it's more fun, since whatever an NPC does, there is the possibility of the PCs figuring out how he did it, and learning how to counter it, and/or learning to do the same.