There can be a market, it is a growth area, there were very few providers (that we could find anyway) when we began home educating 12 years ago but now there is quite a lot of choice. Also My understanding is that there are now many more people home educating than ever before.
Another thing is, and this is just from observation of those I know or who are in our local area. But I think the two groups who are most likely to be intrested in online tutoring are.
A) People new to home education, who may initially lack confidence in supporting their children's learning
B) young people preparing for exams.
Possible reasons for this are. Cost, many home educating families rely on one inco e and many have two or even many children. Many parents are quite able to teach at least up to ks4. Also many people start with a 'school st home' approch and migrate over to "delight directed learning", unschooling or an alternative curriculum or approach that better fits with their family's rythem if life or value system.
For example we ended up using mostly the american sonlight curriculum, as it is very dyslexia freindly, and keeps the parents orgnised, almost matches our value system while still being outward looking. We do however return to a more conventional approach for the exams stage.
Some but probably very few mirror the school system exactly in the longer term.
You seem to be offering a lot of support but possibly the cost may be set a little high for some.
We have mixed experience with online providers some very positive.
We had a good arts award advisor, who chatted with the child on whats app call or message, and provided very good feed back as well as 3x in person.
We have used three diffrent online providers, one was about £8 per week. We used this for ks3 history. It was for materials plus marking and feedback, no face to face/ video contact but was pretty good for the price. However the materials are something my other children were able to work through themselves, with a little parent support.
Another covers maths and English at functional skills leval. This provides online group class for each subject, a contactable tutor including individual sessions if needed, marking, feed back, curriculim materials for up to 24 months and exam fees. That costs about £245 all inclusive. This is what this child needs but the others will more likely self study for igcses.
We also currently use a very good biology tutor for igcse. She charges £ 70 per half term for live group classes, marking and some materials. So about £10 per week. Honestly I wouldn't be able to pay a lot more. This is the best provider we have used by far, and probably the only one I'd be willing to pay for again for my other children.