Not so much. First off, wizardry is only one type of magic, and the only one to require spellbooks. None of the other spellcasters in the game (with the exception of eldritch knights and arcane tricksters, who both learn wizard magic) require spellbooks. So even if for some reason the nomadic society had no wizards, they'd still have bards, clerics, druids, paladins, rangers, sorcerers, and warlocks, plus all those magical barbarian, fighter, and rogue archetypes that aren't outright spellcasters.
Secondly, there's absolutely no reason why a spellbook has to take the form of a book. It could take the form of a set of inscribed runestones, quipu, strips of inscribed leather, beaded thongs, or anything else like that.
Thirdly, while many spells require costly components that can't be waved away with a focus or component pouch, most of those components aren't things that require a city to make. Some of them can be made through non-techy means. Materials or finished components they can't easily obtain they can buy or trade for from other people.
Looking at the list of spells that need costly components and there's a bunch they probably wouldn't need anyway (arcane lock, plane shift) and a whole bunch that just involve crushed or whole gemstones. Plus, those components are for PCs anyway (who are adventuring and thus going into places where they can obtain the components), and the DM can easily say that a nomadic-culture NPC uses different materials for their spells.