Hi,
I home educate my two children age 6 & 4. They have been home educated from the start, so I can't speak about transition to school. I can only really tell you the downsides for us.
So I love home educating and I love spending time with my children, but honestly, the biggest problem I find is not being able to get much time for myself. I am with them all day long, and currently (I think due to some anxiety around covid and the return to groups) have at least one of them in my bed each night. I am hoping that will ease as they get older.
It can be really expensive, especially if you want to go to groups and outings. It can be done cheaply, but costs can spiral easily if you aren't careful.
I found, over the last year, it was quite difficult to socialise. We saw school children going back to school, but guidance wasn't always clear about home education and groups. My two weren't really old enough to socialise with friends via zoom, so it was really just them for most of last year and the beginning of this. On the plus side, it did mean we were able to start socialising again at our own pace, which was slow due to shielding family members, and now go to several meets a week, all of which are currently outdoors.
We live in a city, so this isn't really a problem for us, but I have heard more rurally, finding groups can be tricky to get to, especially if you don't drive. Even in our city, which has great public transport, we find ourselves limited by not driving.
It can be quite stressful, for the parent, because you are taking full responsibility for your child's education. There can be a lot of information on the internet about different styles of education and a lot of resources available to buy. I find it can take up a lot of my time. We are pretty secure in our home ed style and yet, I still find myself wondering if my children are missing out by not doing this amazing thing I just saw on Instagram/Pinterest/Facebook/etc.
Lastly, I find keeping on top of housework really difficult. We're out all day at least 4-5 days a week, which should really mean there's not much to clean for the other 2 days, but it doesn't really work like that 
So, this turned into an essay
I'm worried I made it sound really negative, but honestly, I am so glad we home educate. I could write a post at least double this length with all the positives for my family. Ultimately though, this is a decision for your family. Home Ed isn't the right choice for everyone and you know your DS best.
If you are on Facebook, the Home Education UK group is excellent. It would also be useful to join your local group, if possible. It's really important to know the law and how your LA is. Some overstep their remit quite a bit. The law is different in Scotland to England, so just be aware of that.