There can be two possibilities why you want to use a pirated software. First maybe because the original software is too costly and the second may be because you are tired of using the trial version with limited functionality or with ads. Pirated software and cracks are basically the modified versions of the software on another software with the features of the former.
Almost 99% users will want to use a cracked program for free than the paid one. According to me, it is indeed not a good job to do, but yes it serves the purpose. Indeed you are sometimes vulnerable to viruses, spyware, adware etc. but this completely depends on your choice of application and from where you downloaded it. There are various trusted developers who crack and provides patched software or programs for free. The worthy example can be taken of R.G. Mechanics, Fitgirl, which are famously known for their game repacks, with I don’t think most users will be willing to pay for. Also, there are other developers know for there patched software.
But yes, you will definitely be vulnerable if use patched software for an unknown developer. It may harm your PC/mobile etc. by compromising your online privacy. It may use your gadget for crypto mining thus slowing it down, which is the most common form of internal disturbance. You may get your IP blocked resulting in various security issues. although you will not get any further updates or security patches for the cracked software from the original developers.
So, the choice is completely your. Either be very careful while installing pirated software or encourage the true developers by purchasing their product and value their work.