Well, the politicians probably meant to say “Apple, Google, Microsoft, plus maybe Sony and Nintendo”
i.e. the companies that already have biometrics, nigh-mandatory user accounts, app stores linked to real identities, parental controls, locked down attested kernels, and so on.
If phones had workable parental controls that let parents opt their kid into censorship, that’s better than the give-your-passport-to-the-porn-site approach the UK have taken.
Of course if they have applied it to every OS, not just the big corporate-controlled options, that’s a dumb choice.