routerLinkActive only visually because it only adds a CSS class. Therefore, always add ariaCurrentWhenActive too.
skipLink for big navigation lists
Add specific labels to buttons. e.g. close buttons on many elements should contain the element name.
Hover and focus effect should be equal. e.g. a card with hover effect and close button, should make focus visible on card. For example using :focus-within selector.
Form should use <form (ngSubmit)="..."> instead of click listener on a button.
Add aria-invalid if FormControl is invalid, added by angular material automatically