Oops - in this changeset "foot" seems to have disappeared from changeset/79116201 . I've re-added it.

Not quite sure what the comment means. Possibly related to the JOSM validator flagging that "foot=yes" or equivalent is unnecessary for highway=footway? I can't think of any other reason for deleting "foot" tags.

The "foot" tag disappeared from way/759870454/history among others . What actually happened - did you perhaps auto-apply a series of changes from JOSM or something?

I've just tried the JOSM validator on way/757988391/history (unrelated to this area) and that indeed warns that "foot=yes is unnecessary for highway=footway", which is incorrect.
JOSM warnings do need to be looked at one by one to see if what they are suggestion is actually valid. "foot=yes" is an important tag because it says whether there is a legal right of access somewhere or whether that access is just permissive.

See https://josm.openstreetmap.de/ticket/19862#ticket

I will have used the JOSM validator at the end of the session and will have clicked "fix" to this warning perhaps a bit casually. IIRC JOSM uses "foot=designated" (ideally with designation=public_footpath or such-like) or "foot=permissive" for legal status. IMHO the significance of "foot=yes" is unclear, and I can see why it thinks it is redundant with "highway=footway". But I agree that it isn't good practice to strip off these tags since other mappers may be using them to indicate legal status.

Thanks. It's absolutely true that OSM access tagging is more complicated than it needs to be. access=designated says "designated ways are intended to be usable for the designated purpose(s)". That's not quite the same as the original use of access tags which was to indicate the _legal_ right of access.
In same places where highway=path is used much more than highway=footway "foot=designated" is often used to say "this is really a highway=footway (if no other designated tags) or "this is a multi-modal path which foot traffic has an equal right to use".
In England and Wales (but not Scotland) "foot=designated" was also used (somewhat confusingly) to indicate public footpaths - thankfully now "designation=public_footpath" is normally used there now.
It's annoying that OSM has evolved two values for the same key that can both be true at the same time - a "foot=designated;permissive" way is quite conceivable (although there aren't any at the moment).
Thanks,
Andy

For info - the JOSM issue that was raised for this is now fixed: https://josm.openstreetmap.de/ticket/19862 .