I’ve had 3 British cars!
1963 MGB
1962 Sunbeam Alpine
Currently a 1959 Triumph TR3
Never had a single electrical issue with any of them, if you leave the Lucas electrics alone, as they left the factory, they are rock solid. It’s when you start splicing into them, messing with the +GND, etc. you’re asking for trouble!! Exactly the same as modifying/tweaking a Harley, the only thing you know for sure when you alter a Harley is that you’ve killed the reliability!!!