Chelsea has never been the club to promote youth from academy at a regular basis, but thats because as @ said, our academy were not that good. Now we can see that our academy has come a long way and produces players that shows great potential, like Chalobah. But we still bought alot of young players and will probably keep doing that. It's true that we need balance between youth and experience, unlike Arsenal. But buying young cheap players has lower risk than buying established players who would have higher transfer fees and wages. Young players also have resell value, someone like KDB was bought for 7m can now be sold for at least 15m(I am against selling him btw) that is double the price we bought him. I dont mind buying young players as long as there are experience as well on the first team. And as long as those who truly shows promise to be given a chance, if they are good enough they will make it but I want them to make it in Chelsea.