I built https://mitta.us during Covid. I use it every day and am now working on AI pipelines for the documents saved to it over at https://mitta.ai. It's not a traditional crawler, and only saves what you tell it to save. There's also a Chrome extension to save pages quickly while browsing, and it allows you to remap search in chrome to the console, which then forwards you where you need to go based on the content. Still very much a WIP, but getting there!