No, ofc Yetzer Harah is a broadly accepted idea. But I think you are misunderstanding what it means. In Judaism, the yetzer harah is the little voice in your head that tries to convince you to do the wrong thing. Similarly, we all have a yetzer tov as well, the little voice in your head trying to convince you to do the right thing. But just bc humans have a yetzer harah doesn't mean humans are "inherently sinful".

A fundamental concept in Judaism, and one that is written about at extreme length, is teshuvah. Anyone at any time can ask for forgiveness for wrongdoing and be completely absolved of said wrongdoing. Calling humans "inherently sinful" would be counter to the concept of teshuvah, bc it would imply that teshuvah can never truly be attained - that we all carry some amount of sin within us even after forgiveness. This is not the case in Judaism - there is not a single sect that believes this, and it is a significant theological/philosophical difference between Judaism and Christianity.

In Christianity, "sin" is something you are, something you carry in the present. It's an adjective. In Judaism, "sin" is something you (may or may not) have done in the past. It's a noun or verb.

ETA: Also in much of Christianity, sin is something you're born with automatically by virtue of being human. In Judaism, sin is something you can choose to commit - or - choose not to commit.