Would need human curation to select the best websites in each field.

I think the biggest challenge will be to standardize the scraping process since databases for audiovisual content are very differently structured. Will probably require database-by-database API access/negotiations so that you know how their databases are structured - completely FOSS audiovisual content databases are rare.

I was referring to that you could take ideas regarding UX/UI from it.

https://www.kenmei.co/ may be close to what you want for manga.