Richard Seymour was at his best as an interior defensive lineman. He was such an incredible force that he he could. Not all DEs are what I would consider an edge rusher like TJ Watt or Matthew judon (who got cut by Miami yesterday. Those small quicker defensive linemen are often exposed by a good running game when you go right at them.
Richard Seymour and Chandler Jones and Ty Warren could handle the run and collapse the pocket. We see that with the current defensive line. They don't get sacks as much as they force the QB off platform and scrambling.
The other thing about the Draft and that particular position is that young players - 20, 21, 22 years old - may be great edge rushers in college but face an entirely different situation at the pro level. Bigger, better OTs and schemes keep edge rushers at bay. It's better to spend the money in free agency for a proven player than to draft an edge rusher. Judon was a great pickup and quickly became the most dangerous pass rusher in 2023.
If a team is drafting in the middle to the bottom in each round, DBs and interior linemen are often more available and effective in their first couple of years.