Orphaned subpages [notdone]

Based off of query/69309 but extended to include more than just archives
very shaky since my sql skill is non-existant
Surprisingly good at finding nonsensical pages, which makes sense when coming from such a nonsensical query

SQL

select distinct CONCAT("{{User:Aidan9382/templates/ArchiveDumpEntry|1=Talk:",SUBSTR(page_title,1,LENGTH(page_title)-10),"}}") as basepage_title
from page
where page_namespace = 1
and page_is_redirect = 0
and page_random < 0.02 -- Reduce calculation time when testing
and page_title like "%/_" -- I assume this isfine
and not exists (
  select 1
  from page as basepage
  where basepage.page_namespace = 1
  and basepage.page_is_redirect = 0
  and basepage.page_title = select 1 from STRING_SPLIT(page.page_title, "/") -- If actual page name has a slash then... uh... :/ hope
)
and not exists (
  select 1
  from page as basepage
  where basepage.page_namespace = 0
  and basepage.page_is_redirect = 0
  and basepage.page_title = page.page_title
)
order by basepage_title asc;

SQL

Checking query status...