The thing is, it can be worth it for the right independent school for your child.
Assuming you want a day school, whether that particular school is close to where you live is perhaps less likely.
Some independents will by dry, stuffy and not very inspiring. Others are extremely impressive and offer great stuff. Some will suit your child and others not.
So, as at all stages of education, for anyone who can afford to choose, it’s always best to look at what’s actually available to you and yours and to choose the best based on your child. Often that will be the independent option, but certainly not always.
The errors people make is lumping all state or independents together. The myth that all independents are better is simply a myth. Lots of people think this when choosing reception for their kids too….surely any school with fees must be better. No.
Why might you pay for 6th Form? The school might offer a chance to learn with a cohort of very clever children which will work if your child is one of them. It might offer niche subjects not available elsewhere. It might offer an extensive Oxbridge programme and get large numbers in every year (this isn’t many schools at all) and that might be important to you. Smaller classes might appeal to you. Fantastic A Level results might appeal to you. Some kind of fantastic extra curricular opportunities might appeal to you. Fancy facilities might appeal to you or lovely foreign trips.
Note, not all independents offer all the things on my list. Don’t assume but check they actually offer the stuff you value..and first make sure you know what that list of stuff is. You might find the independents you visit offer all or some or none of it. You might decide to stay where they are or look at other State options with fresh eyes, or you might go.