People put too much stock into getting a manager that 'has won something'. In the end, the vast majority of successful managers have become successful because they have been given a chance by a big club.
Would people on here be interested in Guardiola, Klopp, and Zidane when they were at Barcelona B, Mainz, and Madrid B, respectively? No, the same negativity would be there. But because Real Madrid, Dortmund, and Barcelona gave them a chance, they have now become managers everyone wants.
Nobody would be interested in a manager who kept Mainz up and then got them relegated, nor two second-tier Spanish league managers. But some of the biggest clubs in their respective leagues gave those managers a chance, and they reaped the benefits.