My mobile office has been reduced to a 12" iPad Pro with a 13" MB. All files are kept in iCloud and shared between the portable devices, a MBP, an iMac, and a custom PC.
The two portables together - inside a shared soft case with plastic protectors on each - weigh a lot less than my 15" 2015 MBP, and vastly less than a 17" Dell laptop I tried to use for a while. Having two big screens and one real keyboard is hugely more productive than trying to do everything on a single device.
The MBP gets hauled out for anything that needs more power or a bigger screen - not often in practice, because the battery life isn't anywhere close to being good enough for a full day of work.
I moved to this setup from the MBP about six months ago, and it's been a big step up in productivity. With two fairly light devices I can do almost anything I need to do almost anywhere. It's at least as productive for coding, research, and social as my old non-portable dual-screen Mac Mini setup from a few years ago.
It's not powerful enough for content creation, but that needs extra music hardware and bigger displays, and for now I'm happy to leave the tools for that at home.
As a bonus, the big iPad on its own is also the best ereader I've ever used.
Not to mention, the knife in a Swiss Army knife is going to be way worse than a similarly priced knife. There's a number of things you can do with a $60 knife you can't with a Swiss Army knife.