When touring, both. Bring SPD cleated shoes and also Merrill Moab waterproof hiking shoes.
Vast majority of days use SPD cleated shoes on the bike.
The hiking shoes are mostly for use in the campsite. Days when I used the hiking shoes on the bike include: (1) if my SPD shoes are very wet from previous rainy days and the next day is expected to be dry I might wear the hiking shoes to let my SPD shoes dry out while also keeping my feet drier, (2) there have been days on very rough gravel, cobbles, single track when I did not want to be cleated in and wore hiking shoes, (3) or if it is a sightseeing day when I am staying in one place for a couple nights but want to ride a short distance but am mostly walking that day, will wear the hiking shoes, (4) or a quick ride to the store or pub or restaurant from the campsite.
Pedals, there are lots of options for platform on one side and SPD cleat on the other side. On some bikes I have Shimano A530 (I think that is discontinued now) and on some bikes I have M324 pedals. A few years ago I wrote up a thread comparing those two pedals, but now with many more options of SPD/Platform, that thread is now somewhat dated.
https://www.bikeforums.net/touring/1...l#post18306425
On trips where I might have to ford a stream, also have a pair of light sandals, but sandals are not for riding. Also use those for shower shoes. Sometimes wear the sandals in the campsite too.
***
Non-touring, my road bike has double sided Ritchey Comp SPD pedals. My folding bike has MKS Ezy quick release pedals with toe clips.
***
A friend of mine was on a fully supported foreign bike trip and hit a pothole that he did not expect or see, he was on platform pedals and woke up in the hospital. That said, when I mentioned this before, someone responded with a story that was the exact opposite.
***
I am not buying any more pedals that I can't easily add grease to the bearings. My A530 pedals and many other Shimano pedals can easily be re-greased if you have the inexpensive TL-PD40 tool. My Ritchey Comp pedals have a metal cap that takes an allen wrench to access the innards.
On the other hand I have tried to get the plastic cap off of my M324 pedals and the cap will probably be destroyed if I remove it, thus have not added any grease to them. Not buying any more pedals like that.