The laptops with 2 or 4 Gb of RAM (e.g. Chromebooks) are also likely to have Celeron or MediaTek CPUs which might struggle much more than that, also unless you

The laptops with 2 or 4 Gb of RAM (e.g. Chromebooks) are also likely to have Celeron or MediaTek CPUs which might struggle much more than that, also unless you have multiple tabs open 4GB of RAM might not be that bad. And given a choice between being able to open several tabs all of which are barely functional and being stuck on a single website at at time which runs smoothly I'd definitely choose the later (of course the tradeoff is probably not as straightforward, then again it's not completely obvious to me that optimizing for speed would necessarily result in higher memory consumption). IMO even if they are optimizing for Macs, I'm not sure this approach would make sense (assuming the tradeoff between CPU performance and RAM usage exists) since they are much more likely to have less memory and better CPUs than PC laptops (e.g. you can probably easily get a Windows laptops with 32GB for $1000 or less).