Through the years I've worked in web development it's been ingrained in me that client-side validation is absolutely and completely necessary in all web applications. Seems to me like all the people in the profession are very adamant on using it every single time. The most commonly mentioned benefits are:
- Instantaneous showing of form errors
- Less unnecessary requests to the server
But as we're moving towards the modern web, more and more applications are AJAX based. The simple task of submitting forms takes a lot less time now than it did before and validating on the server and returning errors barely impacts the user experience.
Could it be justifiable to completely avoid client-side validation (for example) on an application that only contains small and simple forms?
EDIT: I would argue that the linked duplicate question doesn't really capture the same example I'm giving here. A lot has changed since 2011. All of the answers on the related question are arguing for user experience whereas in my question I'm describing a scenario where the user experience would be unaffected.
When client-side validation no longer improves the user experience does it continue to rank in the same level of importance as before?