The Topics API is intentionally much less capable than 3rd party cookies. So if Google phased out 3rd party cookies and replaced them with Topics, the abilities of non-google ad networks would already be curtailed. Meanwhile, the same restriction doesn't apply to Google as they can just have the browser track users in much the same way as 3rd party cookies used to do.
So even with Topics, there would be a power imbalance between Google and other ad networks.
The Topics API is intentionally much less capable than 3rd party cookies. So if Google phased out 3rd party cookies and replaced them with Topics, the abilities of non-google ad networks would already be curtailed. Meanwhile, the same restriction doesn't apply to Google as they can just have the browser track users in much the same way as 3rd party cookies used to do.
So even with Topics, there would be a power imbalance between Google and other ad networks.