That means they enjoy your company. They like to have you with/around/near them. I might tell my friend, "It's good to have you around." when she comes to visit me from out of town. I am happy to have her with me.

Your presence is desirable .

when someone enjoy your company and he or she fells good next to you

Hard to say if you are lonely.

在某些情况下最好的事情就是身邊總有朋友。