I think it takes time. I work on a 10+ year old code base (young IMO) and instead of rewriting and probably breaking things unnecessarily we are slowly upgrading things. If you see a var and it’s constant change it to const. if you can fix a bug here change it to async await flattening it out making it easier to read. If you realize this is an object refactor this section to use a class... slow and steady improvements... not sexy just effective