I have spent some time on this too.
I really wanted your approach to work and went down that pathway with this [1], but its one weakness if you have multiple destinations with multiple socket types. It's not uncommon that I have to go between countries with China/Aus, EU, India (kinda-sorta EU but not), and UK plugs. That's a lot of those C7 cables. Also, having 1-2m of cable lets you put the charger on a bedside table when the only wall socket is buried under the bed for some reason, so that adds up.
I then considered one with the swappable ends, like this [2], but the advantage of the cable is that you don't get the 'this room's only socket is against the desk and fuck you if you want to plug a big wall wart into it' problem, plus as above the cable lets the charger ports be much more easily accessible. Also, many models also only have US/EU/UK adapters, without covering e.g. CN/AU style plugs.
And at that point, you're basically using of those old-style universal adapters with the universal AC input and the sliders to change the output, especially given you can now get them with integrated 65W GaN USB ports [3], so why would you fiddle with attachments you could lose?
So then there's this [4] which is so close to my ideal but isn't quite there. It has the cable advantages, minimises additional swappable weight to get different socket types, and you can even put the adapters straight on the charger if you want to omit the cable.
But then I read about abysmal reliability performance and I'd rather not burn down my hotel room in a third-world country. It does have the ends that I, personally, would like but with all of these you're at the mercy of them designing them for the specific wall socket types you need. And at least with this one, the UK one doesn't include a fuse as it's supposed to, whereas IEC C7 plugs do. Further burnination possibilities.
Really, if a reputable manufacturer made [4] but sank an extra ~50% product price into proper reliability and standards compliance, as well as making a whole plethora of swappable ends for all types of wall sockets that fit both the cable and directly onto the device, I'd probably buy it and never look again. I'd even accept a proprietary swappable end form factor with the vendor lock-in risks just because it's basically the utopian ideal of what I want.
But in the meantime, I'm back to using [1] with generic basic adapters for EU and CN/AU on the end of the UK IEC C7 cable. I'll build a collection of C7 cables for each destination and when I travel to only one I'll take the appropriate cable, but when it's multiple destinations I haven't found a better solution.
[1]: Ugreen Nexode 100W GaN 4-port charger: https://www.amazon.co.uk/gp/product/B0B6MZYKTF?psc=1
[2]: Ugreen travel charger: https://www.amazon.co.uk/UGREEN-65W-Fast-Charger-Ports/dp/B0...
[3]: Any permutation of this: https://www.amazon.co.uk/MOMAX-Universal-Adapter-Internation...
[4]: SlimQ 100W Charger w/ extension cable and swappable ends: https://slimq.life/products/100w-3c1a-usb-c-charger
