How hard is it to assemble a modular wood closet tower with drawers?

Verified-purchase reviewers at Amazon, Walmart and Wayfair consistently describe wood tower systems (Aheaplus, Vomavex, similar) as a multi-hour two-person job. The drawers and adjustable shelves add complexity versus simple wire kits. Reviewers who took their time and followed the diagrams generally report clean results; the most common complaint is unclear instructions rather than missing or defective parts.