Also, your US credit score is meaningless abroad. So in Germany and the UK, we had to pay 3-6 months rent upfront to get a place, and other Americans have paid a whole year’s rent in advance.

Tax rates are much higher in Europe! Sales tax is 17% and income tax is 35-40%. Salaries are typically lower than in the US. And in London there is the big monthly Council tax!

The US has a lot of conveniences. There are some states that have inconvenient laws, like no alcohol being sold until noon on Sundays (hi, Georgia!), dry counties (hi, Alabama!), and transportation can be less convenient, but….

Kitchens- many rental apartments in Europe don’t come with a kitchen. That’s right. They are rented without a countertop, appliances, a sink, cupboards, etc. Our experience with it was in Germany.

In Europe the store hours are not typically as convenient- in Germany most stores, even grocery stores and pharmacies, are closed on Sundays. Even here in London, stores are not open as many hours as in the US. Sundays tend to be days spent in parks or at home with family, and as an expat you don’t have family nearby. This can be hard.

Laundry- in London and many other places in Europe, clothes dryers in apartments are rare. We had one in Germany, though. In London, if you’re lucky you’ll have a combi (washer/dryer in one small machine) that is in your kitchen and it takes 4 hours to do a small load, and it still won’t be dry when you take it out, and electricity is expensive. We just use the launderette- well my husband bid the laundry person, not me.

Quiet appliances. In the US, our appliances are all labeled Whisper because they are so quiet. That’s uncommon in London.

Cars- we are car-free here and we’re in Germany, but I was car-free in Southern California (free rideshare app for all residents of our city, free trolley, walkable) and Northern Virginia, too. But all the other 29k Americans my husband worked with in Germany had cars. Even when the desire is there, it’s really difficult for Americans to make the leap to go without a car. You have to carry your umbrella, your shopping, your medicines, coats, gym stuff, etc all with you in good and bad weather. You can’t just lock it in the trunk when you’re living car-free. People seem rushed, because arriving one minute late can make your whole journey time increase by 30 minutes because of the connections, frequency, etc. of the trains and buses. You’re also more vulnerable to theft and losing your stuff. Public transport in London is pricey. Buses here travel 6mph. It can take 30 minutes to go 3 miles.

Reverse Culture Shock- you may expect culture shock living abroad, but Once you live abroad for a few years, it isn’t easy to live back in the US. Your expat experience has opened your mind in ways that your American friends and neighbors can’t relate to and you may find them to be intolerant and scared to get out of their bubble, and lacking curiosity about other people and cultures. Expats often feel caught between two worlds. We feel most comfortable around other expats.

Healthcare- isn’t typically free or better. Depending on your visa, you may have to pay upfront for healthcare as a visa requirement, even if you have US insurance that covers you abroad. Plus, everyone we know in London buys private dental insurance. And many Americans here fly to the US for healthcare. In Germany my husband had to have 3 MRIs and be on morphine for a week until they figured out his health issue, and our professor friend was told he was fine in Germany and then flew home to a South America and had gall bladder surgery, much to his relief. My German language teacher suffered from a painful wrist for months and still was waiting to see a doctor in Germany.

Spontaneity- you need to make reservations weeks or months in advance in Germany and London and in many parts of Europe. Businesses also have limited hours.

I could go on further, but OP covered a lot too.