It's a massive wage but IMO his contract is not the issue, he's simply the best player on the planet and has been for almost 2 decades. Basically, he's been worth it IMO.Which gets you back to gross incompetence. If no one else in the world could get close to affording his wages...then why did they give him such a wage which could and would sink their club? Could have paid him half of what they did and no one else in the world could afford it, still.
They let Messi be bigger than the club, and now they should have to pay for it but we all know they won't have to.
Messi has enabled them to win CL's and get above Madrid in the bragging rights, which meant the El Classico brand went ballistic globally seeing Barca the main beneficiaries with international markets lapping up brand Messi and brand Barca.
The gross incompetence, however, can be aimed at practically every other transfer they've conducted the transfer fees they have paid, salaries each come with and the lack of revenue they've generated through player sales. This element is where I see the incompetence and miss-management.