Why must shipping take sooo long?!

2 pool filters bought on Amazon.. coming from China! Blew the 10 day Friday delivery date so they offered us 20% refund plus the filters when they arrive or full refund in another 7 days. I had a parcel sit on a Chinese runway for a month (so says the fake tracking website the thief directed me to) Had paper mail from LA arrive the next day here in Orange County (the next county south of Los Angeles). Hit or miss.