While many democratic countries impose term limits on their heads of government, legislative members usually enjoy much more lax rules, and often there is simply no term limit at all for representatives and senators. Why is that?
I'm not asking why term limits exist. I'm asking why they're usually enforced over heads of the executive branch and not members of the legislative.
The purpose of term limits is to limit the power of any one individual in government. Legislators have a lot less individual power than heads of state do, so there's less need to add limits to their power.
Term limits are not without downsides. The longer someone does their job, better they are at it (typically). So there's a balance to be struck between limiting power and increasing experience. For legislators the balance falls towards increasing experience.
On a more cynical note, legislative bodies are the ones typically with the most power over term limits, and they have very little incentive to limit themselves.
