Just to be clear: Gmail is displaying ads for free use of Gmail.
If you pay for Gmail (Google Workspaces, previously known as G-Suite) then they do not serve ads.
If you pay for Gmail (Google Workspaces, previously known as G-Suite) then they do not serve ads.
When using any POP/IMAP client, you won't get ads as the POP/IMAP protocol has no provisioning for it. Unless Google injects the ad into the email body (which is near impossible to do reliably) they cannot show ads even if they want to.