"Excess curtailment" implies the existence of non-excessive curtailment. Which is correct, some curtailment is not excessive in a system designed to deliver electricity at the lowest cost.

Batteries are great and are rolling out faster than many realize. But their existence also makes it feasible to rollout more renewables, which will lead to more curtailment.

You can have a very nerdy conversation about how much curtailment is too much and whether you should rollout tech to absorb curtailment before the curtailment even exists.

But implying that curtailment is a big scary thing that spells doom for renewables and we need enough batteries to soak it all up is an anti-renewables trope at this point.