Less demanding Esports and most AAA titles won't be a problem reaching 144fps at 1440p. However the gtx 1080 won't be able to support frame rates this high for future triple A titles on ultra settings. This is perfectly fine because that will also be the case with the 1080ti eventually. You'll just have to upgrade your graphics card in the future along with the rest of us.
Less demanding Esports and most AAA titles won't be a problem reaching 144fps at 1440p. However the gtx 1080 won't be able to support frame rates this high for future triple A titles on ultra settings. This is perfectly fine because that will also be the case with the 1080ti eventually. You'll just have to upgrade your graphics card in the future along with the rest of us.