The age of our current regulars next season:
Suarez: 32
Pique: 32
Messi: 31
Alba: 30
Rakitic: 31
Busquets: 30
Ter Stegen: 26
Coutinho (replacing Iniesta): 26
Roberto: 27
Umtiti: 25
That's 6 out of our regular 10 over 30 years of age. Valverde somehow managed to run this group into the ground without incurring any devastating injuries all while scraping results in the league, but he's sadly mistaken if he thinks he can replicate this next year. Madrid likely won't be as shit in the league and we'll have a proper title race as well.
Not to mention there is no guarantee Messi doesn't decline or Ter Stegen doesn't stay as hot, and oh, our luck will likely even out, it always happens in the long run.
Can't rely on own goals, shit finishing, last ditch tackles and amazing saves all the time.