An ecommerce site is a moving target. A new review widget, popup, theme section, navigation component or checkout-related integration can change the DOM and interaction model without anyone intending to touch accessibility.
That is why recurring monitoring matters.
What ADAFix watches for
• New controls without accessible names
• Form fields with broken label relationships
• Heading and semantic regressions
• Positive tabindex and keyboard-order problems
• Embedded content without useful titles
• New media behavior
• Reintroduced markup problems after app or theme updates
The important distinction is that fixes should remain yours. Monitoring is valuable because the website keeps changing, not because a vendor threatens to remove yesterday's repair when you stop paying.