Backup offensive linemen aren't typically sexy picks, except when it's somebody exotic like Jordan Mailata. But they often are smart moves, especially after the Eagles let a Hall of Fame tackle depart in free agency to replace with a little-known youngster.
It's difficult to say how high Jack Driscoll's ceiling is in the NFL. He doesn't have great length and played right tackle almost exclusively for Auburn and, previously, UMass. Driscoll has played a lot of football though, starting 44 games in college, including some time at left guard as a freshman. He's athletic enough and has nice size, too, running a 5.02 40 at 6-foot-5, 306 pounds.
Sounds like the type of player the Eagles will be able to coach up and find a home for, whether at guard or tackle.
There's no question the need was there.
After Lane Johnson and Andre Dillard, who experienced ups and downs as a rookie, the backup tackles are Mailata, who still has no meaningful football experience whatsoever, and Matt Pryor, who currently projects as the top reserve guard as well.
So whatever position he winds up fitting best at, Driscoll should easily carve out a spot on the depth chart. There's even a small chance he'll be viewed as Dillard insurance - though that obviously isn't ideal for a number of reasons.
I suppose you could nitpick and say there were prospects available who would potentially provide immediate help as a part-time player at another position. But next to quarterback, offensive line is the most important position on the field, so the Eagles were probably wise to add there.