I’m currently going through this phase, it’s quite lonely at times, and I do sometimes have the feeling of being ‘unwanted’. I think extended periods of loneliness could lead to depression and low self esteem, as well as anxiety when going through normal problems in life because you don’t have emotional support. Depending on the person, it may lead to you becoming desperate for friends, meaning you’ll accept anyone as your friend even if they treat you badly, or aren’t compatible with you.
On the other hand, you can learn to feel comfortable alone and find things that you enjoy. I feel that I’ve learnt a lot about myself recently that I wouldn’t have, had I been socialising, as I’ve had more time to self-reflect. Over time, you may learn to have higher standards for yourself as you learn to have fun alone, meaning that you’re less likely to just blindly be friends with anyone who’s available. In the past I’ve spent time with people who have been toxic and detrimental to my self esteem due to my desperation to have friends, so an upside of having no one around is that there is no one to potentially put you down or make you feel bad.