Guitar exercises are a slightly controversial topic. Some consider them an invaluable tool for development, and others see them as a distraction from the real goal: playing songs.
I've included them here as I think they have a place in most guitarist's practice routines.
For beginners, exercises like the Caterpillar permit the player to focus purely on finger movement and the sound produced without the additional layer of complexity a piece of music demands.
For more advanced players, a well considered exercise can rapidly expose and shore up weaknesses in their playing.
However, I always encourage continuous song learning - and if the material chosen is appropriately challenging, you may find your exercise routines are right there within the music.
It all depends on your goals. If your current issue is as broad as:
"I'm too slow."
You will likely find improvement by working through guitar exercises at incrementally increasing tempos.
On the other hand, if your current issue is more like:
"I'm having trouble transitioning from this F chord to this G7 chord in bar 4."
Should you go practice guitar exercises? Probably not. You should probably practice bar 4.
Generally speaking, I recommend working on exercises at the start of a practice session, for no more than 5 minutes at most. Don't make them the main focus of your practice. You won't find a huge improvement on exercises on a daily basis, anyways.
The real performance improvements on exercises will come over the course of weeks and months.
So, get your fingers warmed up, practice them for a few minutes, and then move on.