But you’re assuming that your drone will be 100% reliable with no chance whatsoever of a flyaway or other malfunction. That drone will probably never exist!
The rules are valid in almost all circumstances and it would be difficult to legislate individually for the small number of circumstances where it may be safe to fly with different rules.
Your response implies that you think that it’s ok to obey the laws you agree with and ignore the ones you don’t. Sadly, laws and legislation, once passed, are not negotiable by the general public and consensus doesn’t enter into it from a legal point of view. If you opt to break the rules, the chances are pretty good that no one would notice. However, if something does go wrong (and it will, eventually) or someone who knows the rules reports you, there would be no defence against the potential legal and financial penalties that could be imposed.
More importantly, we’ve really only got the rules we have at the moment as an attempt to control irresponsible use of drones in the past. The more that people break the rules, the more (worse) rules will be introduced. Contrary to what some people seem to think, the legislation is not their to make drone flying less enjoyable, it’s there to try to make it safer for those not involved.