When you say "hard to compare" do you mean not in the same way? "It would be better if...." is used very frequently in English to introduce opinions, for example ".....it stopped raining", "...the government sorted out Coronavirus", "....my neighbour tidied his garden." Could and would "Bylo by lepší,..." be used in all these cases?
Exactly, we cannot reliably say which expression is used more or less in the respective languages without comparable and representative corpora. When we can say something from our educated guessing we usually have an order of magnitude difference or more but this is not the case here.
It means the same and is used roughly as often, impossible to say if it's used a little less or a little more. It sure can be used in all the examples you named. Sometimes other expressions are more appropriate, such as "Bylo by fajn, kdyby..." for "It would be nice if..." or "Bylo by prima..." or "Byla by paráda..." for "It would be cool/great...", or simply "Bylo by dobré...." for "It would be good...", etc.