I'm not really seeing the point here. Lever espresso machines exist and continue to be manufactured. La Pavoni and Olympia continue to make lever espresso machines that work just fine.
A lot of the reliability concerns from tools of the past are frankly quite well justified, and to this date we continue to sell and produce tools that are dangerous if not properly operated.
Older machines, like La Peppina and Caravel, are open boiler machines, meaning the boiler is not pressurized. The way the water flows means they have excellent temperature stability for espresso (the boiler is of course at 100C, so the brew temp is right around 95C).
Of course, an open boiler means there are a lot more potential safety issues.
A lot of the reliability concerns from tools of the past are frankly quite well justified, and to this date we continue to sell and produce tools that are dangerous if not properly operated.