Writing software is about problem solving skills which improve with practice. Often the process involves breaking down a problem into smaller pieces and breaking each of those down, until you know how to “solve” each problem.
Writing down each “solution” and stringing them together is then the actual “programming” part of this activity … which brings with it a whole new layer of “problems” to “solve”.
It’s as much art as it is accounting and the more you do it, the better you get at it.
Source: I’ve been writing software since 1982.

















Puppeteer and Chrome were my go-to, but that was before AI bots started hammering sites, and Cloudflare and others started offering blocking processes to stop them.
I’d be surprised if the service you’re currently using will be effective for much longer.
As for text comparison,
lynx -dumpwill give you the text anddiffwill show you the changes, but as you mentioned, that won’t show you the graphics and banners, unless the site actually uses accessible content.