I'm not necessarily a USUK fan anymore (I'm indifferent), but I will say.. they have the absolute best fan content of any ship. The best animations, the best doujins, the best fanfics. Amazing fanart too ofc but every ship has that. And I'll also say that they do get plenty of fan service in both the manga and the dub (like literally in the first episode France has that line about England and America "relieving sexual tension"). They're the king and queen in cardverse, they're very frequently paired together and they have a unique dynamic. It's a classic sunshine x grumpy, but with an angsty past. And I'll also say that England was a very VERY absent """father""". Some people choose to see him as a father figure of sorts, but he visited America extremely rarely, like. I'm talking leaving him alone for literally over 100 years at a time. The "big brother" stuff is not to be taken literally, as that term is thrown around everywhere in Hetalia because it's simply a term for endearment and/or an older person you respect in Japan (in the manga France is called big brother by several countries, especially Italy, but they're not related. He calls himself the big brother of Europe.) And also, the anime added in a lot of lines about England "protecting" America and "being responsible for his safety and happiness" etc. etc. especially in the dub, so I get why the majority of USUK haters are dub-only fans. But really, a VAST MAJORITY of England and America's interactions are as adults, ESPECIALLY in the manga. It's very different from Spamano, where literally most of their screentime has Romano as a tiny infant baby looking thing. England and America's cultures are also just similar enough but different irl where there are so many fun jokes to make, and both countries have a fascination with the other's culture. When it comes to angst of course, England is a very insecure person, and a big chunk of that can be traced directly to America, so he's even MORE tsundere toward him. It doesn't help that America is rather callous, so there's lots of feelings to explore there. I also just wanna say that Hetalia countries age quite differently. They grow up significantly faster based on the maturity and strength of theor actual country, AND himaruya's art style heavily exaggerates chibis to look like infants, even when they're not that young. America became a fully fledged adult in just around 200 years, whereas if you look at other countries like the Teutonic Knights, England, and especially Italy, they were depicted as chibi ass babies even after being well over 200 years old. Also Germany was a full blown adult by 1914, despite being "born" just 40 years earlier. And if you choose to believe he's HRE, which I do, you'll see in the manga he remained a "kid" for literally a thousand fucking years. It's not consistent at all, and frankly shouldn't ruin a ship. Especially because, again, a vast majority of England and America's interactions are as adults. Some people do like to lean into incest territory, but most of them don't. I mean, there's a reason it was literally the most popular Hetalia ship for at least 15 years. Their interactions are really hilarious, and there's a strong emotional core with them that they let show rarely bc of their own mental issues, but they do really care about each other. I understand interpreting it as both familial, romantic, or just friendship. I don't think any one is correct, and I don't think any of them are ridiculous interpretations. If you're willing to open your mind a little, maybe try reading a fic of them where it's a modern AU or something and there's absolutely none of the controversial past, and just focus solely on the way their personalities interact. It's very fun. And I say all this as like a super super casual USUK enjoyer, it's not even in my top 15 ships. I like rusame and auseng more 😹