Surely, the solution is to acquire a whole bunch of old, slow laptops and hook them together as a build cluster! :)

Old thinkpads (2012ish) run for a hundred bucks and some change, and some of them support up to 32 GB of ram, IIRC. The battery is a generic and replaceable component, too. They can last a lifetime! Or at least until FF et al renders 32 GB insufficient.

Now I don't know pmoriarty's situation at all and don't want to assume anything either, but, if someone has a "pretty old, slow laptop on which I've been running Gentoo for a long time" without upgrading, there is surely a reason for that. Suggesting that "hundred bucks" is something you can spend just to get faster build times might work for a well paid developer in the 1st world but many developers are not well paid so cannot afford the luxury of upgrading their machine willy nilly like that.

While upgrading for money works for some, less bloated software would work for everyone + no need to spend money to get acceptable build times + even if you have a super computer, you compilation times gets a lot faster. So aiming for less bloated software feels like a more noble goal than trying to convince people to upgrade their hardware.

Hey, I'm sorry, I didn't mean to come off making assumptions or prescribing advice. My intent was to illustrate that "new computer" doesn't have to mean "shiny, expensive, newly-manufactured computer". On reflection, my words do reflect my biases that investing one-to-two hundred dollars in such a setup wouldn't be a cause of much concern for me, and I regret that I assumed likewise for the readers.

I totally agree with you that less bloated software should be our goal. Although, realistically, if you're compiling a modern web browser you don't have much of a choice in the matter (unfortunately). I don't think that reducing bloat by an order of magnitude (i.e. a difference that would impact compile times) is on the radar of Chromium or FF.

Since you're a gentoo user, you probably already know that, but have you tried using compressed memory like zswap? I find that I very rarely swap out to disk since I enabled it (and tuned to my needs):

https://wiki.archlinux.org/index.php/Zswap