Is solid wood always better than engineered wood for bookshelves?

Solid wood lasts longer and refinishes, and r/BuyItForLife threads consistently push shoppers toward it. But the reviewers we read also acknowledge that well-made engineered-wood pieces from established brands (Sauder is the most cited example) have outlasted multiple IKEA Billy replacements in real homes. For the price, engineered wood with a thick back panel and a proper wall anchor is the pragmatic middle ground.