> Even Shannon’s passions for investing and studying the stock market started with Betty. She became intrigued by the market and filled the home library with books on investment strategies and economics

Nowadays for many people it would be her browser's bookmarks and history getting filled with links to investment and economics sites and articles, rather than the home library getting filled with books.

I wonder if that makes it less common for one's interests to spread to others in the house?

With books, they get left around in living areas, ready to easily enthrall others who pick them up out of idle curiosity. When put away they are probably in bookshelves shared with others.

With bookmarked links there would be less opportunity to stumble across someone else's bookmarks. Everyone's bookmark list is on their own account, or even their own device.