Most of the people thought Front-End Development is easy and anyone can learn within few days or it's Just HTML , CSS etc.
But Actually it's not !!
YES IT'S NOT !!
It's as difficult as learning Back-End Development or any other Top-Notch Technologoies.

So, here are some more specific challenges that front-end developers may face:

Cross-browser compatibility: Different web browsers can interpret and display HTML, CSS, and JavaScript in different ways, so front-end developers must ensure that their code works consistently across all major browsers.

Performance optimization: Front-end developers must be mindful of how their code impacts the performance of a website, particularly on mobile devices with limited processing power and slower internet connections. This may involve optimizing images, minimizing the use of resource-intensive features, and using performance-enhancing techniques such as lazy loading.

Responsive design: With the increasing number of devices and screen sizes that people use to access the web, it's important for websites to be responsive, meaning they should look and function well on any device. This requires front-end developers to have a strong understanding of how to build layouts that adapt to different screen sizes and resolutions.

Testing and debugging: YES, testing and Debugging is also cosider as part of Front-End Development. Front-end developers must be able to test their code to ensure that it is working correctly, and they must be able to troubleshoot and fix any issues that may arise. This can be a time-consuming and challenging process, especially when dealing with complex or poorly-written code.

Keeping up with new technologies: The field of front-end development is constantly evolving, with new frameworks, libraries, and tools being introduced all the time. Front-end developers must stay up-to-date with these developments in order to remain competitive in their careers.

Collaborating with other team members: Front-end development is often a collaborative process, and front-end developers may need to work with designers, back-end developers, project managers, and other stakeholders to build and maintain websites and web applications. Effective communication and collaboration skills are therefore important for front-end developers to possess.

So, finally I would say that It's not Easy. Learning any skill even it is front-end , back-end , blockchain , cloud-computing , AI/ML etc. is not easy each of the skill require time, need hardwork and lot's and lot's of practice.