The point is that I'm much more willing to draft a QB high than a RB, even if the QB is expected to be a backup. Both Miles Sanders and Jalen Hurts were drafted 53rd overall. I think Hurts was the better pick, but the problem with arguing that is a lot of Eagles fans are also PSU fans who vastly overrate Sanders. Drafting a RB high only really makes sense when you're already a contender, like for example Sony Michel helped the Patriots in their 2019 SB run*. But I think right now they'd rather have drafted a backup QB in that spot, such as Lamar Jackson. Many fans actually agree with trying to find a good RB in the later rounds or as an UDFA, but they don't apply the same considerations for positional value when it comes to (backup) QB. In addition, even if a QB rides the bench for 3 years, they actually maintain their value unlike a starting RB. Compare Jimmy Garoppolo and Leonard Fournette.
EDIT: *) 2018 season