The Front-End job is one of the largest required jobs, and it is not as few as some think, and it takes a long time to master it and to build a list of projects as your business. Therefore, it is not a final condition that you learn the Back-End path with it.
There are many companies that like to specialize and like the person who works in one field and is professional in it.
There are many developers who like to deal with colors, fonts, and the front-end part and do not like to deal with databases or the Data Layer part in general, and this is up to you. There is also the opposite of those who do not like dealing with colors, fonts and visuals at all.
But, if you are one of the people who have time to learn both fields and have no problem dealing with colors, fonts and the data part, and you want to be a Full Stack Developer, then there is no problem and this is a nice thing and many companies prefer it, but you should know that you need a very long time to master domains together.