I'm going to be in the third year of university in a month. I'm satisfied with the software part of my bachelor but I feel like I lack in practice in practical implementation. Would getting an Arduino board and playing around with it worth it and useful for me?
It depends. If you don't have any knowledge about microcontrollers it might be useful.
However, Arduino hides a lot of concepts in their libraries. If you want to go more indepth check other systems like STM32 or PIC.
You also can do both, start with Arduino to get a rough feeling, continue with another.
More important is WHAT you try, don't stop with LEDs/switches, but check communication protocols like SPI, I2c, UART etc. And learn what timers, interrupts etc. are and how to use them.
As already stated in previous answers, there is no clear-cut answer to this kind of question. It all depends on what you want to learn.
If that can help, I will share my personal experience. I studied computer science for only one year at university. Then I stopped to continue on my physics major. But as I never lost interest in computers, I continued learning on my own. I started playing with Arduinos just because it looked like a fun way to learn some microcontroller stuff and low-level programming. The barrier to entry is extremely low: in no time you get your LED blinking, and from there you can start exploring plenty of possibilities. The Arduino IDE and core library make it extremely easy to make simple programs, but they are quite limited when you want to get more serious. For many people, this environment, plus extra downloadable libraries, is all they need to achieve their goals. For me, it was a stepping stone to learn lower level stuff, like direct hardware access, use of the avr-libc, and even assembly programming.
Today, what I love most about Arduinos (or, rather, the AVR microcontrollers at their core), is their simplicity and understandability. Today, when I disassemble a program I have written, I can understand basically everything: the C runtime initialization code, the memory allocation, the way the compiler translates my own code... I find it extremely rewarding to reach such an understanding of a (kind of) computer system.
The same level of understanding would be (for me) impossible to achieve on a typical PC. Even though I use Linux, which is Open Source, and I have access to the full source code, the whole software stack involved in running even the simplest program is overwhelming. The kernel itself is like millions of lines of code. Even the assembly language of an x86 (or x86_64) is something I find way too complex for my taste.
In conclusion, the Arduino has been for me a very rewarding learning experience. If you want to get your hands dirty with bare metal programming, I definitely recommend you get an Uno, or something similar, and start playing with it. Once you get your first program running (and that takes no time!) start looking under the hood: read the source of the Arduino core (it's short and very readable), read the datasheet of the microcontroller, start poking the hardware, take a look at how the compiler allocates memory, how it translates your source code...
I don't think there is a should or should not about it, do you want a low cost experimental setup using the C language to toy with ideas and concepts without a massive outlay or proprietary software or NDA's to get chip data that ties you to a single company then why not? You can get Arduino clones very cheaply from the likes of aliexpress etc as well as prototyping kits. While the Arduino IDE is a relatively primitive editor you can use any programmers editor you like to compose your C files and use the Arduino IDE just to do the final compile and linking and upload/burn them to the target device. It can be done so cheaply that even if you decide it does not inspire your imagination you won't have wasted hundreds of $! Just spent a couple of tens of $ to accumulate a significant micro-controller playground! Assuming you already have some kind of personal computer or easy access to one.