I have built applications using React and most recently Vue2.
Both are very very similar and if you are familiar with one you will be able to pick up the other quite easily.
In regards to webpages both are capable of doing the same things and fit the same uses cases.
That said however if I was to start a greenfield application today, I would choose React.
The reason for this is that react is better known, it is easier to find solutions for, and it has more mature guidelines for things like project structure and best practices.
Vue is good competition for React and it will certainly help keep it on it's toes.
However in regards to longevity, I feel React will be around a lot longer than Vue.
React has the full support of facebook and is being used by other major vendors.
Vue is also used by some big sites, however it has no official backing that I know of and is maintained by a "Benevolent dictator for life".
In a year or two I predict that I will see another article with a title along the lines of "Switching From React To <insert new hotness here>". It is very unlikely in my opinion that I will see a "Switching From Vue To <insert new hotness here>" article.
By not available what do you mean?