You can donate to keep the quality. I agree the ads based system is against the spirit and philosophy of Lemmy. Lemmy isn’t a reddit and this is where the dev of sync did a mistake.

Donating isn’t the only possibility. The dev could make the app a one time payment (I know he said it will come) without free version. If people want to use Sync, they have to pay for it. It’s for the job and hours behind it.