I don't know it this will be the case for Cuba, as it's somewhat differently placed on the map, but Russia tried DST only and had to switch to standard time and then stayed there.

Some people absolutely loves DST for some reason, but it creates stress and mental problems for people, especially in the north. The long mornings are somehow worse than the short evenings. Technically it shouldn't matter what the clock shows, but when society insists on things happening at a certain time, whether or not the sun is out becomes important.

For the Russian case see: https://www.bbc.com/news/blogs-news-from-elsewhere-28423647

Because it's generally senseless, and particularly for them even more so given their location.

Because DST is the wrong time; if you look at the legal implementation of DST, most countries carve out exceptions for fields where lying about the time can obviously lead to death and destruction - navigation being perhaps the main one.

What everyone missed is that DST could itself lead to much greater loss of life than we might have lost had the use of DST been mandated all the way through to e.g. large naval, air or spacecraft.

And as research into DST continues, this seems to have been not merely an abstract possibility was missed, but _the actual outcome_. DST is quite literally killing people by the thousands.