A website is more than a collection of isolated pages. Internal links show how subjects relate and give readers a route to the next useful answer. The original article argued that they matter to visitors and search engines. That remains a sound starting point, although keeping someone on the site longer is not an end in itself.
Help people continue
A link is useful when its destination answers a question that arises while reading. A product article might point to instructions, terms or an example. Describe the destination in the link text. “Learn how to choose a size” is more helpful than “click here”.
Google recommends crawlable links and descriptive anchor text. That helps its system find pages and understand their context. It does not guarantee a higher position; the destination must genuinely fit.
Build routes that make sense
Review important pages as a newcomer would. Can you go from an overview to deeper information, and then back to a useful choice or next step? An article need not link to every other page. Too many links may make it harder to read.
Check existing links when moving or removing pages. A link to an error page breaks the route. On a large site, finding pages with no incoming links can reveal forgotten content.
The value of internal links is coherence. Readers can explore their question and the site shows how its parts fit together. A few well chosen links do more than an artificial target number.