The SOLAS regulations that came into effect were mainly around lifeboat provision.

One cannot build a liner with full compartmentalisation, and nothing in the two Enquiries said otherwise. Titanic wasn’t a warship. No other civilian ship - even today - has fully watertight compartments.

It didn’t sink because of its design. It sank because it was driven at 22.5 knots into an iceberg. If you want to know more, read the book I linked in my original reply to OP or visit Encyclopedia Titanica.