Why much of the High Seas Fleet remained underwater

Why were many High Seas Fleet wrecks left on the seabed?

Depth and recovery cost made many wrecks uneconomical to raise, so leaving them in place saved money and effort.

Many wrecks lay too deep for economical recovery with the available methods. Raising them would have cost more than the likely value of the salvaged material. Leaving them in place also spared the Royal Navy further expense and effort. Depth and cost were practical limits rather than proof that none of the wrecks could be salvaged.