WCAG 2.2 removed SC 4.1.1, Parsing (Level A). I maintain that valid markup has important benefits despite no longer being required. We may find it possible to write good software without static analysis, construct a building without blueprints, or make an accessible website without validation. They remain good practices.
WCAG’s normative text describes outcomes, not how to achieve them. Validation is but one part of the process of achieving the necessary outcomes.
Let’s not interpret the removal of SC 4.1.1 as permission to ship known errors.