No. It helps no-one else. By definition an orphan is the record of a submission to the network of work meeting the criteria for generating a new block... but the submission was rejected by the network (usually because someone got there just before you). It's a local record, kept in your wallet.dat file. So it clutters up your wallet without becoming part of the blockchain.

It's part and parcel of mining, whether through POS or POW. The cleanup tool just gets rid of this clutter from your wallet.

You can also clean your wallet, and contribute to the network, by moving your coins to a fresh wallet.  It's slightly more costly because you pay transaction fees. But it helps to keep the network moving and alive.

Staking also keeps the network alive... but the current rate of return is no incentive to hold coins. By my own primitive calculations the current 'interest' is about 3.8% PA. The 5% in the official documentation is 'compound' interest based on reinvesting all generated coins. IMO this should be increased to 10% simple interest, with premiums for coins held above 90, 180, 270, and 360 Days (say 12.5%, 15%, 17.5% and 20%). This would encourage people to hold staking wallets, thus securing the network, and help to stabilise the price on exchanges. It could also encourage adoption by merchants who could benefit from holding currency reserves.
Just a thought.

Of course then the orphan removal tool would become more significant, as moving coins between addresses would incur the penalty of lost interest and coin-age. ATM the penalty is negligible.