Since you are sharing data with other users, Row Owners would not work well for you here, because this will prevent users from seeing other user’s data. Same with user specific columns. They also prevent others from seeing the data. I’m guessing with what you want to achieve, I would avoid row owners and user specific columns.
To get counts, what I would do is create a template column that combines the Email and Date columns.
Then you can create a multiple relation that takes that template column and relates it back to itself.
Finally you can create a rollup column that sums the steps through that relation. That will give you a total number of steps for each user/date.
Now if you’re looking to only show the aggragated total for each date, then I would also consider adding a Row ID column to your step table. Using that row id, then create a single relation that links the email/date template back to itself. Create a lookup column the retrieves the Row ID. Finally create an IF column to compare the row’s Row ID to the lookup Row ID. If they match, then return true.
What this does is only put TRUE on the first row for a user/date. So if they record steps multiple times in one day, only the first instance will have a TRUE, but every user/date row will have their total for the day. This allows you to filter only the TRUE rows, so you don’t see multiple entries per day.
This might cover most of what you want, unless you’re looking for some additional breakdown or summarization of data.