That is not anywhere near the same as being friends with them.
I think whether or not friends are necessary depends on the person. People who are extroverted will feel like friends are a necessity. Meanwhile, introverts like me, are perfectly happy to be by themselves. Some introverts may want to have friends but only minimally or in small amounts, others are fine without them at all.
Introverts do not always lack social skills, its just that social interaction is exhausting. Telling someone to push past this may not be possible. Not everyone needs to be an extrovert, the only people that say that or think that way are extroverts. And, unfortunately for us introverts, the majority of people are some level of extrovert.