Many organizations produce their own local guidelines for accessibility outlining what they’re looking for and their preferred solution for accessibility issues. This is a list of examples.
Accessibility Programs
Accessibility Guidelines
Accessible UI component libraries
To be clear, the most accessible components are the ones built into the browser. When you need something that goes above and beyond, like a tabset, it is nice to not reinvent the wheel.
Accessible UI Component Libraries Roundup by Raghavendra Satish Peri at DigitalA11y is a good list of places to start.