Almost 10 years Man United did not win the EPL. Even 7 coaches have been selected to try to deliver the championship title but failed. After Sir Alex Retirement, Man United did look bad. In fact, many large transfers have ended up failing. When Ten Hag arrived, they began to improve even though they did not have a championship but Man United's performances were promising. They have made good use of transfers, but there is one player who could possibly be the solution. Since they currently do not have a number 9 striker, Maybe Man United can buy Kane as this solution. But Tottenham are unlikely to release Kane to an English club.
It is true that David De Gea is the last name ever to win the EPL trophy with Man United in the era of Sir Alex Ferguson. After the change of coach until the era of Erik Ten Hag, exactly one decade United had never won the EPL and the Champions League. United success under Ferguson was the culmination of the golden generation of their academy and won various trophies, after the Ferguson United era experienced a transition period and could not win the EPL or the Champions League.
Ten Hag has a heavy burden to bring his squad to the EPL trophy after more than ten years of not winning. If Ten Hag had financial support like Pep Guardiola, maybe this could have happened sooner.