I did this for a while. I went so far as to built a highly advanced web crawler webapp that was better than the Internet Archive in a lot of ways.

But the modern web has made this unreasonable. Every webpage is 99% junk (CSS, JS, HTML structure, tracking pixels, UI images, navigation links, cryptominers (I joke)) and 1% content. You need a smart AI system to pick out the good parts, otherwise you'll quickly find yourself schlepping hundreds of gigs of junk to just preserve your favorite websites.

The better idea is: if you love information, back it up. Collect the knowledge from the website, not the website. And then preserve it. Create a free ebook. Or sell it on Amazon kindle. That'll last a lot longer than the website will, and any HTML backup of the site you could possibly make.