Apart from 2008 being "way back" seems accurate. Like Australia in the late 80's/early 90's they stopped focusing solely on track mid 2000's, this investment sped up once Olympics were confirmed (2000 Sydney/2012 London).it comes from way back. from the Olympics 2008, then London 2012, the investments and the budgets of Sky (the sponsor, not the team) the national lottery, and HSBC.
the hard racing there and all the youngsters starting from the track and going on to the road. we're 10 years from Wiggo's TDF win. that 2012 year made things even faster.
the foundation was already there. the talents came out, at home. for example the situation here in Italy is not good. no WT team, just one, ONE indoor velodrome, sponsor and funds come and go. what GB built in the last 10-14 years is huge.