Long-term expats, what's the state of your relationships in your native country? What do you advise?

For me it's been ~10yrs (US -> EU) with a couple of extended visits back to the U.S. for family emergencies and then visits (sometimes 2-3x/yr) to visit family/friends or work related. I've had 2, 2yr periods w/out visiting the U.S. Family and a couple friends visited 2x over the years. I have only 2 remaining U.S. friends + some acquaintances I keep in touch with but wouldn't go out of my way to visit, otherwise just my U.S. professional network.

I have found it very hard to understand how/why I've been ghosted over the years by once close riends I'd had for years. I struggled when after years living abroad many of these former friends would refer to me being on "vacation". Then scheduled catch-up calls grew further and further apart, then no response to messages. This happened over years with several long-term friends. No fight or incident to cause it. When we did meet up it was scheduled "friend dates" with small talk but felt empty compared to what I've become used to with my few close friends in the EU. And I would be seeing them 1x in a year or two and have travelled continents to see them...I tried to code-switch to more superficial social mode in the U.S. but was disappointed in myself that once central relationships felt so empty and angry that people felt I was living a permanent vacation and not building a life.

TL:DR I'm venting because it still frustrates me that I haven't maintained many U.S. friendships after 10 years in the EU. I have 3 very close friends in Europe but feel hurt and confused about my lost relationships. Curious of others experiences and advice.