some of them not so serious, just ideas. know about path dependence and network effects
instead of using several hundred different languages localized in small areas. to avoid inaccessible knowledge and feeble understanding among people. make it possible to communicate internationally on almost native speaker levels. it is often underestimated how much effort it takes to learn a language well - it can easily take a decade. while one may be able, with great effort, to communicate in basic ways after a relatively short time, this is far from how and what native speakers are able to communicate. effective intercultural communication increases the communication bandwidth and makes a difference for improved mutual understanding which helps us with leading discussions, being diplomatic, inclusive and compassionate. by opening up interaction with more people and cultures, reducing the diversity of languages may increase the diversity and richness in other aspects. instead of ideas being locked away behind insurmounted learning curves, we could have access to more thoughts. learning a language is also practically required when wanting to move to a foreign country and because of that, shared languages increase mobility. imagine how much more difficult it is to move between multiple different countries in europe and build a living in a new country because of the many different languages.
humans that do not understand each others language are similar to humans that never discovered language at all.
example of cultural separation through language: the internet is separated into language bubbles. if one searches for a foreign language string, for example something arabic. one will probably find that almost all of the results will be exclusively in the foreign language, and many will probably be unknown sites - this is another bubble. that is what the speakers of that language only see. different language cultures have their own versions of popular internet services and social platforms and may have no need to interact with, or take much note of, for example, the anglosphere on the internet. this kind of diversity leads to duplicated effort, reduces innovation that would come from the competition of ideas in an extended market, and even fosters isolation and danger because countries can go to war - in which case speaking a different language would probably be a big advantage, but are we enemies?
having a country adopt the language of another country seems rarely even thought of. what would happen, is perhaps just the following: more people will understand more other people. one should at least question fears of "cultural suicide" as a supposed consequence of sharing, as well as questioning the assumption that people must have different languages in localised areas. dialects and languages develop naturally but the reach and efficiency of the means of communication have increased. one argument against shared languages is that dangerous memes might spread faster, but on the other hand, a response might be more effective as well.
fahrenheit -> celsius
the byte is not even conclusively defined as being 8 bits long
use more ascii based mathematical notation to teach. traditional notation is like being made for blackboards and uses many little "paintings" for symbols to save space, but because of that becomes time consuming to learn, more difficult to use with computers in this format and more difficult to uncover its meaning. this is a chance to make knowledge more transferable. use non-serif fonts and perhaps english word variable names. consider how unacceptable it is to write computer programs with that many symbols and lack of meaningful variable names, as is typical in mathematics. i would argue there is some middle ground that is better than what is common now. formulas may be efficient, the notation is not, if the required contextual information is considered
make well informed choices. do not just follow the marketing and popular opinion, because it might support network effects that hinder positive change
more interfaces: libraries, http, command-line
big-endian -> little-endian
bsd, mit -> gpl