Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

• Decreased performance, as DRM is often hooked deep into event loops and adds non-negligible overhead.
• Decreased privacy, as DRM often requires pinging an external server constantly.
• Decreased security, as DRM is a black-box blob intentionally meant to be difficult to peer in to, and has been the target of attacks such as code execution vulnerabilities before.
• If you own a game but don't have an active internet connection, DRM may prevent you from playing the game.
• If you own a game but have multiple computers, DRM may force you to buy multiple licenses when you're only using one copy at a time (c.f., a physical CD with the game on it).
• Eventually, a DRM company is going to go out of business or stop supporting old versions of their software; if you want to play an old game that had that DRM, you won't be able to even if you own the game.
• &c.

DRM exists to "protect' the software developer, i.e. protect profits by making sure every copy has been paid for and to force people to buy multiple copies in certain cases. DRM never has and never will be for your (the consumer's) benefit.

I gifted my dad a steam game for his birthday. He is a big Linux fan so he installed it on his Linux system. Now he can't play it for more than 5 minutes before denuvo freezes not only the game but somehow even manages to freeze the complete system and he has to reboot.

Had to return the gift. It's a shame he really wanted to play it

Some DRM systems abuse security designs. Regular applications aren't meant to be running at kernel level (ring 0) and should be running sandboxed at a user level. There are kernel dev blog posts that talk about this. It's basically like making an arm move by poking a brain with a stick. Anything that can then access that stick or the hole you created can make at brain do whatever they want.