Defending needs to be done as a unit and certainly this season, and in a lot of games over the last few years, Everton do not defend as a unit.
A full-back is no longer a defender. They are just as important going forwards as backwards. Welcome to football in 2022.
I've gone through, in painstaking detail and literally named the full-back options those clubs have for left-back, that the top PL clubs (the only ones that could afford him this window as they can't abroad) have options there. Why would they look to change that midway through the season when they're not desperate, which none of them, bar Chelsea, are? And Chelsea have 3 LBs on their books.