Looking on the internet deeply has found these results:

more hollow is the most popular phrase on the web.

hollower 174,300 results on the web	more hollow 1197,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	What could be more hollow than to die alone... unloved? Each night when I pray, the words become more and more hollow.

hollower

174,300 results on the web

more hollow

1197,000 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.