I gripe about the PayPal Cashback because it doesn't have any sort of transaction notifications and I hate the website but it's a solid card otherwise.
Both Sync and Citi are said to be similarly awful with disputing charges and customer service (I haven't dealt with Citi yet but Synchrony hasn't thrilled me in our interactions) but from a value standpoint, the PayPal is much better than the DC with no minimum redemption and no FTF as long as you make sure never to carry a balance because the APR tiers are awful.
Alliant has a 2% everywhere card, PenFed has a 1.5% that earns 2% if you are military or get a checking account with them ($500 minimum balance to avoid a fee), Fidelity has a 2% card if you have accounts with them, BBVA has a 1.5% thats 2% with a checking account... there are plenty of options out there if you're willing to do the work.
I grabbed a Discover IT Miles so I get 1.5% on everything and a 1.5% match after the first year for an effective 3% cash back rate. There is also HSBC and Chase Freedom Unlimited offering capped variants that offer 3% for the whole year.
If you use PayPal a lot, the PayPal Cashback makes sense. If you have a business account though, like most who sell on eBay have, you will likely have to open a personal PayPal to apply.
So i assume it won’t be an issue to have another Synchrony card, even though I don’t use the Car Care card all that much?
Nah, I have four Sync cards. Sync has a $100K max credit limit per customer cap and most cards additionally have a $10K online cap (you have to make a call to Credit Solutions to get more). It's possible to get a lot of Sync exposure with all the merchants they have cards for.
I think the Citi Double Cash at 2% is a good overall card for cash back. I'd have one myself but my credit union already offers a 2% card. However, I may open one someday to add a MasterCard to me repertoire (I only have one but it's a corporate card). I'm not sure if the Double Cash ever offers a SUB, but I may jump on it if I ever see one in the future.