I've been home educating for over a decade now and there were a lot of factors involved in it that have changed over time, but when we started it was mainly that it had been option my spouse and I were aware of & had considered purely because we had issues while in school & my oldest has SEN that were apparent then and had already experienced issues with adults because of it.
We had a few issues at playgroups and similar that left me uncomfortable sending my child to school when he wasn't able to clearly communicate for himself. I know there are a lot of jokes about how kids answer 'what did you do at school today' in some funny ways, but having a child who literally couldn't answer that question, and had already experienced adults putting him and those like him to one side because of his communication skill problems just left me feeling that I couldn't do that to him, not for 6 hours a day for weeks at a time. I think it would have harmed him and that he needed that one-on-one/two education to develop the communication skills he has now.
By the time my second was old enough to go to school, home educating was just our lifestyle. I didn't think to do any different until my oldest was in Y9, weighing up his options for KS4 and we were butting heads a lot especially for English because he struggled so much and maths because he was so good at it, much better than me (having someone else do most of the academics with him from 15 on helped our relationship a lot). He looked at different options, we did that with him, toured a couple places, and through that my second child who was Y7 at the time was very sure and discussed with me how she didn't like any of those, we talked through what she wanted and by chance there was a new school locally that specialized in what she wanted more of and she chose to take the chance of doing an in-year transfer.
With my younger children, I discuss it as in primary, we home educate because we adults choose it. At secondary, they get to be involved in the choice, but we still do some 'afterschooling' / holiday education in areas I know aren't going to be covered as well as their father or I like as we have different priorities to any school systems. It's mostly practical and life topics, but also some humanities work - it's still part of our lifestyle as a family: my now about to be Y12 oldest got the Calling Bullshit book once it came out in paperback earlier this month and we're going to go through it and the syllabus the authors put up together alongside his college coursework this autumn & when I showed him the book was arrived, he was excited (though to be fair, not as excited as he was when we were discussing him never having to do Chemistry equations again after getting his results - science iGCSEs were rough doing as an external student).
As for social life, yes it's more difficult, as a pp said, you have to put in more active work, isolation is an issue particularly for older kids that you have to keep an eye out for, we basically have to build in the consistency into our lives. I have seen home educated kids with terrible social skills, but I've also seen school educated kids with similar social skill issues sometimes for similar reasons either in their home life and/or, to a lesser extent, SEN. I've left HE groups because of behaviour issues - bullying does happen in HE groups, sometimes by the adults - and while HE might amplify certain parenting issues like the ones who won't tell their kids no (though I think at teen years that levels out with school ones), I don't think it's an issue with home education, it's finding the right social environments and ways of building those skills for your child specifically. It takes more work than is typical for schools, but you could end up with a school situation and needing to deal with that too. No guarantees on it either way.