> there is no libre hardware if you want top performance, common architecture

Performance is definitely a difficult sacrifice. Consider however that your general computing could be split into a privacy sensitive component: sending emails/messages, assembling documents, banking website, etc, and a privacy insensitive component: compiling OSS, playing games, etc. Composing/sending email for example is not computationally demanding... so one might use a high performance Intel machine for insensitive computing and a lower performance libre machine for sensitive work. It's not perfect (web browsing can be both private and not, and demanding and not) but a refinement of this separation approach could be an interim solution until high performance libre hardware is available.