Agreed.
I started playing when I was 13 (I'm 38 now) and I'd say it took me a good 8-9 years to finally get to a point where I realized I needed to play for the song rather than individual glory. I started out quick learning all the Metallica and Megadeth I could in my first couple years. I had chops early on but not a lot of wisdom to go with them.
Someone might listen to the bass parts I've just done on our forthcoming release and think - "he's not bad, just adequate, etc." I picked my spots. I'm playing in a band with two guitars, keys and full orchestration at times. It wouldn't work if the bass was all over the place doing whatever. I play for the songs.
The biggest compliment I got was from our keyboardist, a much younger guy, who was mixing and assembling everything. I turned in my tracks and he didn't have any notes. He just told me I nailed it perfectly with timing, and did just the right amount of melodic flares and fills. That made me feel good. I don't want to be seen as an overplayer.
Now in cover bands? That's a different story. I will do the most ridiculous bass fills at the end of stuff like Journey or Bon Jovi just to amuse myself.