In many places it's a legal requirement, not just good practice. Regulations like the Americans with Disabilities Act, Section 508 in the US, and the European Accessibility Act point to WCAG 2.2 Level AA, and accessibility lawsuits are common. WCAG 2.2 is also now an ISO standard.
Beyond compliance, accessibility widens your audience and usually improves the site for everyone: clearer structure, better contrast, and keyboard support help all users. Much of it is built in from the start at little cost, and expensive to retrofit later.
Updated July 2026