Are any shipping methods useable anymore?

About 10-25% of my USPS shipped items are running behind or lost in the past month. It’s getting worse by the day, approaching 50% this last week. It’s absolutely out of control. I have had to issue endless refunds with no hope of recovering the funds. Completely stopping using them as a carrier going forward unfortunately.

Also for some insane reason eBay shows ground advantage delivery as 2-5 days? In what universe is that shipping method that fast. I’ve tried shipping some things via FedEx ground instead but with them I get hit with random weight charges 2-3x what the items actually weigh.

Is UPS a viable option? They are nearly double the cost of the other carriers.

Also any way to get eBay to show realistic shipping times? Ground advantage from CA to NY showing as 2-5 days raises buyers expectations to the level I can’t meet, and shipping via a faster method wouldn’t be possible to price competitively.

I believe unreliable shipping may be the death of the ability to sell on eBay if not addressed.