Regarding dripless shaft seals:
The possibility of catastrophic failure is rather low, or I assure you I wouldn't have a dripless.
Examination of any approved installation will suggest a robust product that works in an obvious and non-mysterious way.
The bellows does need to be replaced on a schedule, something like every 7 years. That requires a haulout. Mine is probably 10 years old, and my haulout has been delayed by the mess we're all in, but it looks fine nonetheless.
It is true that one of our local boatyards declined (policy has since changed) to install dripless shaft seals after a failure in the Transpac. Much was made of this at the time. I reason that the vast, successful experience of commercial and pleasure vessels using dripless shaft seals without incident trumps individual calamity and (in the local case) hysterical not-my-fault blamecasting.
Personally I don;t think dripless technology is even controversial. Tenders' experience warns of fuel spills, note taken. I do carry latex and hose clamps for an offshore emergency such as failure of the bellows, but the catastrophy would be only loss of motor power (you could still run the engine in neutral for battery charging).