It's not just changing ways of playing, in order to increase creativity, we have to change the way he sees the game, increases his vision, and improve his on ball skills to execute such vision.
Of course nothing is impossible, but time is limited to drastically change the way he plays. Plus, it's not just changing his playing style, a lot of things have to be improved in order to execute this style of play we are talking about, and that doesn't include just basic skill with the ball, but reading of the game, and vision. Things like these can't be taught, or we wouldn't have gave up on the likes of Guarin and Muntari all those years.
Restricted yes, restricted players deserve restricted thinking in all honesty.
There's also very little gain in us to help him rediscover his play to compensate for his physical decline in the long term, especially when his time here is on the count down timer.
I would very much rather we get rid of him ASAP and invest in someone who naturally plays in this multidimensionality.
Basically, it's very easy to convert a Robben to play like a Figo when he loses his speed. But we are more dealing with making a Dirk Kuyt and turning him into Messi, it's impossible.