I think that Bikeshare has over 300,000 members now. Of course, only a tiny fraction will be using the service every day, but for comparison, in the 2021 census only 15,000 Torontonians said their main mode of commuting was by bicycle (of course, conversely, there will be much larger number who occasionally commute by bicycle) .
The other point is that half of all bikeshare trips take place on Bloor-Danforth and Yonge, so the impact of Bikeshare is particularly concentrated. Anecdotally, whenever I'm on those streets it seem like a non-trivial fraction of bikes.
(from
https://www.toronto.ca/legdocs/mmis/2023/pa/bgrd/backgroundfile-240804.pdf)