* Flexbox being widely supported (a lot of css is just positioning/ordering content)
* Standard style libraries doing most needed appearance stuff in HTML.
* Most brochure sites being sublimated into Facebook for Business/Squarespace/Shopify/Facebook Messenger or some other chat interface. A "nice-looking" website beyond available templates will be worth less and less.
* SaaS continuing to grow and offer hosted solutions for specialized websites/web applications. Already seeing this a lot with restaurants.
* Available React components continuing to grow - you will be able to develop a heavy front-end application using 90% existing modules. React will be bigger than jQuery because of this and because minor use of jQuery for style reasons will fade along with heavily customized CSS.