This is somewhat the difficulty of balancing the needs of governments. A short term/term limit leads to more inexperienced people doing the job. That's good in

This is somewhat the difficulty of balancing the needs of governments. A short term/term limit leads to more inexperienced people doing the job. That's good in some ways - keeping new ideas coming in or keeping people from doing the job far too long. On the other hand, it means some large portion of the legislature is people who are more or less still learning. The process of writing good law that avoids unnecessary downsides, or simply understands the downsides and works to mitigate them isn't something you can just pick up over a weekend, especially when there aren't many people to learn it from. As you say, it's easy to point to the folks who have been in office forever as being an issue, but there's also staff and lobbyists and other unelected roles that are hard to get rid of the influence of. At the end of the day, someone needs to be the expert, either on the vast array of issues that can come up in national government, or in how to actually do something about those issues.