Hm, I'm kind of confused by your perspective here. Do you only have a single thread of tasks you're doing at any given time on your machine, all of whose resources are torn down and rebuilt from scratch when needed? I use my current laptop both for work and personally, and in my personal workspaces alone, I have at least half a dozen browser windows with ~20 tabs representing research that I'm doing or a task that I'm organizing; everything from gift-buying to medical devices for a family issue to building a new workout routine for the pandemic. You can rack up tons of relevant tabs pretty quickly in these scenarios, and there's really no advantage to closing them in any well-managed environment (ie one that has non-rudimentary window management and a browser/extension that handles idle tabs with negligible ongoing resource use).

I probably have hundreds of "productive" tabs open, and that's before even getting to tabs that are serving as an "L1 cache" version of a read-it-later service. And all of this comes with extremely quick clean-up; once I buy the gift/finalize the routine/purchase the item, it's trivial to close the entire window for that task.