Over the past 10 drafts the Saints have used 8 picks on O linemen in the top 4 rounds including these 5 first round picks:
'15 - LT - Andrus Peat #13
'16 - RT - Ryan Ramczyk #32
'20 - C - Caesar Ruiz #24
'22 - LT - Trevor Penning #19
'24 - LT - Taliese Fuaga #14
It's frustrating because O line is considered such a safe investment yet as you can see, the results can be mixed. You draft a promising LT prospect and he turns out to be a perplexing Pro Bowl Guard. You draft one of the best RTs in football but his leg falls off. You draft a Center to play Guard and it turns out he's a Center. You draft a raw but talented LT only to find out he's an up and down RT. And so it goes.
On paper they haven't drafted that bad. Injuries were always an issue. They could never get on the same page health wise.