By completing your 'A' levels with reasonable grades or better, you are demonstrating that you have an adequate amount of grey matter to any employer and capable of absorbing the technical stuff.
That is not to say all is lost without them for those going down the Modular route. Provided your GCSE maths and physics and English language are sound, then the EASA written exams will not prove to be insurmountable.
Averaging 90%+ in them (all first time passes) will indicate to any employer you may well be the right stuff even without 'A' levels