An air taxi firm "might" not care about your school education, but every single airline will.
As previously said above, the recruitment agencies sifting through vast amounts of similar CV's will quickly throw out your application before any chief pilot has read it.
Airline websites themselves state a requirement of usually at least A-Levels.
You hint in your post that you want to go onto Airline work. Well if that is the case, I would strongly suggest you get at the very least maths and physics GCSE's done.
Being able to talk about putting in the effort to get your GCSE's will also make you shine at interview.