I (am not spanish but living there more than ca. 9 month every year) have tested personally ca. 93, 94 or 95% of all small ferries to islands (up to the North-Cape) or crossing Fjords, lakes, rivers etc. in Norway, Sweden, Aaland, Finland and Germany, furthermore Scotland, Canada etc. in the last circa 35 years personally with car. So i generally know about what i am talking.
Especially in Sweden, Aaland, Germany and Finland are many many ferries in 1-man operation since decades - and i have never had an unsafe feeling. It is the same as with buses, coaches, trains, smaller airplanes etc. - there is only 1 driver also - and a high grade of automatisation or manuell help as a strong cable from both sides.
F.ex. in trains and trans the driver has to press all 30 seconds a "dead-man-button" - if not - the train is automatically stopping. Similar system is also possible on ferries, f.ex. that an anchor is falling down then directly. Like an autopilot in airplanes the ferry-driver of a modern small ferry press only the start-button - than the complete trip is operating 100% automatically - including automooring, autocharging etc. . The driver has some video-screens and all under control - but the crossing goes automatically.
Because of the always rising up salaries of staff, crew, workers etc. automatisation for to reduce the number of working people onboard and in ports so much as possible is the future.
Is also in all other businesses similar - as f.ex. big (car-)factory halls with mostly robots working or supermarkets without cashier.
Similar as these former jobs (petrol-service, tram-cashier, metro-driver, 3rd man in cockpit) are today away
https://traminator.at/wp-content/uploads/2017/09/03-742x1030.jpg
a lot of jobs around and onboard of ferries will be in the future away, f.ex. also all "mooring-people".
Then the point of view is different:
Crewmembers has other wishes than ferry-customers and tax-payers.
So if you think that the 80ies and 90ies was better on/with norwegian ferries - full ok.
And sure not everything in the today norwegian-ferry-system is perfect - but i have another opinion and think that it is much better than in the past - and much better - and cheaper also - than it would be with state-owned ferry-companies.