Girls was essentially just Chris though, so technically the band didn't break up, he just stopped calling it Girls. He couldn't keep permanent band members so he reverted to using a solo name.
You're really underestimating the importance of Chet. If you need further proof of his influence on Chris' sound, listen to Lysandre.
Lysandre had a few good songs but couldn't start to compare to Owens' work in Girls. Hoping his next effort is stronger. Less flutes would probably be welcome.