Fred and Maguire have 94 caps for Brazil and England respectively. Those players aren't "the problem", the problem is when those players are your best players, or key players.
We should have focused on building steadily, keeping those good solid professionals as the foundations and slowly replacing them with better players who become the new first team regulars. You could win a title with Maguire and Fred (at peak) starting 5-10 games. It's when they're starting 35+ you might struggle.
Instead of building properly, what we constantly do is chuck money at quick fixes, who then need to be replaced themselves (Casemiro, AdM, Lukaku, Varane, Sanchez, Ronaldo, Zlatan, Cavani, Schweinsteiger), or back the wrong horses out of poor judgement/romantacism and end up lumbered with dubious characters on huge salaries that we cant move on and have to hope come good.(Rashford, Martial, Sancho)