medical leave is quite the concept, you choose to get a surgery, so the company then needs to cover your responsibilities by assigning your duties and tasks to other workers, increasing their work load, so you can stay home and recover, and at the end of that leave, you, the worker whose been forced to increase your workload, gets no additional compensation or paid leave, but should simply enjoy having been a small unpaid part of others medical care, while the company still makes as much profit, and pays as many bonuses to their management as they always have. sure, sounds fair.

Is it actually incorrect? I don’t think it’s necessarily wrong, but it just sounds bizarre or Shakespearean if you use it when it’s not an auxiliary verb.

“I’ve no need for that.” is a perfectly cromulent sentence.