Argue over semantics all you want, the practicalities don't change.
The point is no-one can be made to wear a mask in England any more; all anyone has to say is "I'm exempt" and that will be the end of the matter; anyone can self-certify an exemption and since masks ceased to be mandated, no-one is legally required to wear one.
This idea that some businesses are going to somehow be able to 'enforce' masks as a condition just isn't realistic. TfL's attempts to get legal backing for their ludicrous stance failed and backfired on them; mask usage on the tube is around 50% at best (though very variable depending on location, time of day, etc).
And on the practical level, I largely agree. This is an area where custom and practice predominate, and that is welcome. It is the legal level that I assert that the role of "exemption" is a red herring, and is potentially misleading, for the reasons I've stated before - the
legal concept of exemption was abolished in England at the same time as the requirement to wear masks.
Where I choose not to wear a mask, I do so based on the principle that the law does not require me to wear one, and I am exercising my choice as to whether to do so. I pay heed to the requests of venue (including railtour) operators, and allow that to inform my choice - and I write this in full awareness that my tolerance of mask wearing distinguishes me from you and many others on this sub-forum.
On TfL, on which I use contactless so the technicalities of which conditions of carriage are applicable don't apply, I abide by the contract on which TfL operate their services. That contract recognises the concept of exemption, and if I were entitled to exemption, I would make the claim under contract, not under legislation.
I dig in on the semantics because semantics matter. Covid has been subject to a lot of myth making and lies, from partisans of all kinds. That has not helped in a difficult situation, where many factors are subject to reasonable if heated debate. The law changed so that it is no longer legally required to wear a mask. "You do not have to..." is a different statement from "You are no longer required to..." - and it is the latter which is now the legal position in England.
In that context, the use of accurate terminology matters. It should be enough to accept that masks are no longer legally required. Extrapolating beyond that to come up with some weird concept of exemption adds confusion, distracts from what has changed, and leads to confusion about what it means.