Friends hasn't aged that well for a 90s sitcom.
I would beg to differ on that. Friends is still fresh even though it's first season aired 18 years ago. I don't know whether HIMYM will still be that fresh in 18 years time.
I don't think that the cast of HIMYM has the closeness that the cast of Friends had. The Friends cast were being paid different amounts in season 1 and season 2 before they decided to enter into collective bargaining for equal pay. Jennifer Aniston and David Schwimmer had their pays reduced to match the lowest paid cast members.
I read that Jason Segel plan to leave HIMYM after this season to further his movie career and the cast of HIMYM still get paid different amounts after 8 seasons.
I wouldn't read too much into that. The Friends salary thing is pretty much unique and shouldn't be a benchmark on how close a cast is.
A much better gauge for me would be to watch the gag/blooper reels for each show.. when people mess up or goof around you can really see how comfortable they are with each other and having seen them all for each show (yeah.. i love bloopers reels
) i can say that each cast seems pretty much comfortable and close with each other (and HYMIM is far more racy at times
As a contrast watch the gag reels for Community.. especially the ones from the later seasons and see how they react to Chevy Chase. You can feel that the others are not really including him in their antics that much and try to keep a distance.. anyone who's familiar with the background workings of the show knows why that may be the case.