Well, you are just one of the (majority of) people who apparently don't care about being tracked by google. Me personally, others in the comments and maybe OP don't use anything google related, have custom ROMs without gapps and avoid Google like the plague. So it is a concern for us, using Sync would open the door to google tracking.

Others have pointed out that even if you pay for pro, Sync still requires Play Services.

You seem to happily Google products, so my point wouldn't apply to you. I just thought that most people would be concerned about google and tracking and fingerprinting and all that stuff, since we are in Lemmy and the Liftoff sub.