For me, the simplicity offered by the built-in bookmark system in Firefox is what makes me use it regularly. The moment I decide I have found an URL I might want to look up later, I hit ctrl + d, add a few quick tags, close the site and move on. It takes me less than 10 seconds and has lowered the bar significantly for adding a bookmark. No cognitive overhead is incurred by choosing an existing folder from a (deep) hierarchy, or trying to come up with yet another category in a sub-folder somewhere.
That said, I might move on to a self-hosted bookmark solution in the future that adds the the option to locally archive a webpage, but until then I'll keep doing what I'm doing, because it really works for me :)
I think the key is not trying to use it to replace bookmarks. That takes deliberate work and commitment.
I began using Hypothesis to write "replies" where the comment mechanism was non-existent/unreliable/cumbersome (e.g. on very old content or HN threads, or blogs where the author is likely to not tolerate dissenting opinions, or forums where I don't already have an account, etc.), or instances where I couldn't resist jotting down a response that I had no intention of actually posting publicly (because e.g. being heavy on snark). Eventually you gradually build up a personalized data source that is richer than just the bookmark tagging system (and also includes pages things that you would never think to bookmark deliberately but have later discover some need to revisit it despite that—ever fished something out of your past without having bookmarked it, but were able to relocate it years later because you could recall something about an HN thread that you participated in?). I continue using bookmarks and tags—which, like you, I treat it as as close to a zero-friction act as possible rather than meticulously filing it away in a hierarchy. Using Hypothesis, though, is a supplement to ordinary bookmark usage—an additional resource.
> I might move on to a self-hosted bookmark solution in the future that adds the the option to locally archive a webpage
I recommend using Zotero to capture snapshots but otherwise continuing to use browser-based bookmarks. My relationship with Zotero is similar to Hypothesis—having known about it for years, I only started using it recently (ca. 2020). But it's great. I should've been using it all along.
For your use case, however, I recommend also getting into Hypothesis. I always used browser-based bookmarks (and still do), but I've gotten a ton of utility out of Hypothesis since I began using it. It's weird, because I came at it slowly, having known about Hypothesis for a long time—my initial impression being, "yeah, okay, kind of neat or whatever", followed by not touching it for years.
The problem with browser-based bookmarks is that you're limited to the title* and URL for recall, plus your own tags. With Hypothesis, however, you can quote from the page in question, marking up specific passages, and then also add your own comments about it (plus tags). This is in fact really the only way that I use Hypothesis—when I feel like scribbling something in the margins. This, however, in a way ends up emerging as a replacement for much of my bookmarks-for-recall use, too, even though it's never really the point. Because the storage model includes the contents of the quoted passage and the text of your own annotation, this additionally grants you, in a limited way, the ability to do partial text search across the contents of the collected pages. As a result, I end up using Hypothesis far more often to relocate something than I do with the bookmarks manager nowadays.
It would be great if this functionality became standard for all browsers (and it might still; folks on the Chrome team have suggested they're serious about adding annotations to the browser in some form). With Mozilla deciding that selling premium plans to a commercial, closed-source SaaS is in their financial interest, however, it seems virtually guaranteed that Firefox's built-in bookmarks will remain deliberately limited for the lifetime of Firefox as a product, in order to funnel people towards Pocket, unless/until Chrome does something to make them feel pressured to change.
* NB: you can technically override the name, I guess, but I've never done that and always let it default to the title. Firefox used to have an additional description/comment field, but this got removed from the UI. I suspect it was rarely used. I can't say I did anything with it more than a handful of times. Hypothesis's UI for actually resolving (i.e. highlighting) the fuzzy anchors really does alter my behavior a lot towards this direction.