https://al-shabaka.org/briefs/the-systematic-torture-of-palestinians-in-israeli-detention/

The recent case of Samer Arbeed highlighted once again the systematic use of torture against Palestinian detainees in Israeli prisons. Israeli soldiers arrested Arbeed at his home in Ramallah on September 25, 2019. They beat him severely before taking him to Al Moscobiyye detention center in Jerusalem for interrogation. Two days later, according to his lawyer, he was hospitalized as a result of severe torture, and lay in critical condition for several weeks. A judicial body had authorized the Israeli Secret Service, the Shin Bet, to use “exceptional methods” to extract information in this case without going through the courts. This led Amnesty International to condemn what happened to Arbeed as “legally-sanctioned torture.“

You’re right that a state can commit terrorism just like a group can, but the key issue here is whether the state works towards being held accountable and towards achieving a long term benefit for all its benefactors, investors, assets and the society it’s providing for