Is a full mechanic's tool set better than buying ratchets individually?

For someone building out a first kit, comprehensive sets like the DEWALT and CRAFTSMAN 189-to-247-piece kits give the best dollar-per-tool ratio and include sockets, extensions, and wrenches in a case. Pros and serious hobbyists generally end up buying individual high-end ratchets (Gearwrench 120XP, etc.) and pairing them with socket sets, since the ratchets included in bulk kits are decent but not best-in-class.