Always used Squoosh [1] for that. It does the job perfectly but its a bit heavy as its an electron app, I would not be paying for an image convert app, but I guess Mac users are more used to pay for everything. It seems that it can do bulk, I'm not sure squoosh can though
(After searching I can't find the Electron version, did it disappear?)
(After searching I can't find the Electron version, did it disappear?)
[1] https://squoosh.app/