Most SaaS help centers fail the same way: the article says "click Settings", but Settings moved two releases ago.
When I built a 196-article help center for a B2B SaaS, the rule was simple: every step gets clicked in the live product before it ships. 609 screenshots, 17 categories, 84,912 words.
It is slower. It is also the only way a help article actually stops a support ticket.
If your docs were written once and never re-checked, start with your 10 most-viewed articles. That is where old screenshots hurt most.