Out of place outros of 90s rock songs

There are 3 songs that immediately come to mind on this but I imagine there are probably more.

Epic - Faith No More
In the meantime - Spacehog
Glycerine - Bush

All 3 are standard rock songs, with glycerine being a bit on the slower/lighter side I suppose but the other 2 being a bit heavier. But at the end of all 3, once the "main" part of the song is over we get an instrumental outro that isn't anything at all like the rest of the song. Going by memory I think Epic and ITM are both soft, slow piano while glycerine was something else.

I was a bit young during this time period, was this a common "thing", and if so why? I totally get if a hard rock band wanted to do a ballad or lvoe song or something soft that was different than their main image, but I mean that would be done in the form of an actaul song and not just slapping 20 seconds of soft piano at the end of a normal song I would think.