I have ds similar ages, and there’s definitely two types, those that go out clubbing and the home birds. With computers/gaming/social media etc, you don’t have to physically go out to socialise anymore, You can do it from the comfort of your gone.
However, at 25, he should be working full time, saving money, making plans for the future. He’s not going to do this off his own back, so you need to intervene. Sorry to say, you’ve made life too comfortable for him at home.
Start making changes. From now on onwards, he cooks a meal once a week, empties the dishwasher, puts the bins out. Gradually introduce more jobs ,laundery, cleaning etc).
Sit down and help him write a cv and apply for jobs. If necessary, get him on a course (or make plans for next year) to improve his qualifications.
Regarding socialising, , encourage him to join a club. It can be anything - badminton, Warcraft, historical reenactment, tiddly winks etc.