The ISO layouts for the UK have a two-row enter key.
https://en.wikipedia.org/wiki/British_and_American_keyboards
US keyboards don't. There is a backslash key above the single row enter key. Which is a key I have no real great use for. Maybe it rocked in the MS-DOS days but backslash doesn't really need that priority place.
So look at the Logitech keyboards for the UK. They offer one model with the true layout, i.e. a double height enter key. The rest have some US keys with UK labels on.
Now look at Microsoft. Again there is some massive backslash key instead of an ISO UK keyboard in all its glory.
What happens is that they take the US board and change a few of the key caps. They do not go to the effort of doing it properly.
There are other layouts, for example, German, that should have the big enter key.
Standards might not be optimal solutions. But at least you know where you are. You know what to expect. But with keyboards nobody sticks to the standards. If you look at the Logitech ones for instance they all have different fudges, such as arrow keys mangled together differently, just enough to trip you up if swapping between Logitech keyboards. Then things like rounding off the corner keys including escape. They do these awful design decisions on far too many of their keyboards.
The tenkeyless requirement is reasonable, laptops don't tend to have the num-pad. But is there a tkl keyboard out there with a standard ISO layout? Not if you combine that feature with wireless or a desire for backlighting. Nevermind switch choice.
Some people struggle with an Apple keypad due to the different modifier keys. God help anyone having to press a few keys on any of the ZSA boards. Might as well learn Dvorak keyboards. Or go all the way with a chord keyboard. QWERTY works and we all know it is not the best. But standards are not kept to when you move out of the US layout.