How long would Messi be the one to save Barcelona

How long would messi continue to be the one to save the Catalan in most of there games. The world best player has been in Barcelona since when he was small and even since then he has been consistent for the club,which he score back to back very season . Also the player set new record for the club and in the football history every season.
The Catalans have dominated La Liga over the last 10 years, winning eight titles since 2009, but 'just' three European Cups.
It's good but it's not enough, not when you have the greatest player in history at your disposal.
And especially not when your biggest rivals are out there winning three Champions Leagues in a row between 2016 and 2018.
Which is why European glory has become an obsession for Barcelona and a burden, one they've repeatedly buckled under in recent seasons, with last year's capitulation at Anfield proving particularly hard to take. The classy and industrious Frenkie de Jong has undoubtedly rejuvenated the midfield but the plan was for his former Ajax team-mate Matthijs de Ligt to do likewise at the back.
The centre-half never arrived, though, instead opting to join Juventus, and Barca are now arguably counting the cost of failing to inject new blood into the centre of their defence.
Gerard Pique and Co. came under intense pressure in Prague. They were breached just the once, when Jan Boril toe-poked home an equaliser early in the second half.
But, in truth, that was only because of the brilliance of Marc-Andre ter Stegen. I think the club need to take off there mind form the star player because he his getting old everyday. And that is going to effect the club when the player leave the club.