I would disagree. All of the problems that you mentioned, such as "the layout of the thumbnails", "the regularity of updates" and "something to render a screens

I would disagree. All of the problems that you mentioned, such as "the layout of the thumbnails", "the regularity of updates" and "something to render a screenshot of the website to a thumbnail" can already be solved and parameterized to such genericness to be sufficiently usable for this use-case and, I'd surmise, most others.