If you can’t beat them, join them
Definition 1 of 1
Pro Tip 1/3Adaptability
This phrase suggests adapting to a situation by joining a successful group rather than continuing a losing battle. 
Their software is too dominant in the market; if you can't beat them, join them.
Pro Tip 2/3Colloquial Use
Used more in informal conversations than in formal writing or speeches. 
Everyone's using that app now; I guess if you can't beat them, join them.
Pro Tip 3/3Pragmatism
Reflects the idea of being practical and choosing the easiest or most beneficial path. 
She started supporting the new policy at work – if you can't beat them, join them.