I can give you some context:
First, the numbers are universal and independent of language and character sets. 100 in English is the same as in Chinese and it is the same in every country on earth.
Second, numbers are used everywhere and in every country, phone "number", house "number", zip code "number", birthdays or significant dates expressed as "numbers".
Then there are hacks or games kids play because they rhymes with something. Some times teachers use these hacks to help kids memorize math formulas. For example square root of 2 is 1.41421, the math teacher taught everyone my in class just remember it says "just a tiny little bit" in Chinese, which a the time was a common expression for casual "bribery", which I remember to this day.
To many non-English non-alphabet speakers in the world, it is far easier to memorize numbers then names or spelling of a foreign language. That is why everyone has a phone "number" and not a phone "name"
But does it mean every number combination is valuable? No. There is a lot of speculation in this space and I personally don't have any numeric only domain names, but I do understand why it is valuable to someone.