MacOS’ English keyboard is great for typing in Spanish and French. As I’ve posted recently in other threads like this, I don’t know why other operating systems don’t copy them for their defaults.
Default English keyboards in Windows and Linux are awful for typing in English (which includes needing easy access to some accented characters, among other things). I accidentally learned to type on the International layout so I’m very familiar with it—unless you often need to make a very wide range of accented characters, wider than you’d need for French and Spanish, it’s a worse layout than the default macOS English keyboard because it gets in the way when you don’t need those. AltGr is like the macOS default, but entirely much worse. Everyone, please copy them, they’re the only OS with a keyboard layout good for typing in English, which, it’s 2020 so that’s a big WTF.
[EDIT] examples, option = alt except remember it's positioned a little differently on macOS
option+c ç
option+s ß (german too!)
option+\ «
option+shift+\ »
option+e, deadkey for ´ which you can apply kinda like in US International
option+u, same for ¨ (I'm hitting space after to type the decoration on its own)
option+`, same for `
option+shift+/ for ¿ (or option+? if you prefer to think of it that way)
And that's just the stuff directly relevant to typing in Spanish and French (and German). Most of which are also relevant to fluent typing in English because we have lots of loan words and phrases from those languages, and quoting from them is also common. Then there's punctuation, currency symbols, and so on. All are better than any alternative I know of, let alone any other default keyboard, and if you never press option while typing you'd never even know they're there (that is, they never get in the way otherwise)