When you don't want Apple, Samsung or Google, and who can blame you... look into OnePlus. The 11/12 have some of the longest security updates in the industry, though buying older and used tends to cut into that timeline. Stay away from the Nord series, however. There will likely even be aftermarket OS options after EOL from LineageOS and the like. HMD/Nokia has also been known to line up an occasional handset for extended security updates, but I don't have any recent phones of that nature to recommend on that front. (Edit: otherwise, if it was last year, I'd tell you the Nokia XR21 - which would have been perfect.) Unfortunately, long OS security feature updates with Android are kind of the domain of the expensive flagship models for the most part, which also means copycat hardware deletions on the handsets that mimic Apple's toxic design trends, like the loss of microSD storage expansion and headphone jacks. There are exceptions from Samsung, but a lot can be said about whether you're willing to put up with Samsung's build quality, poor security track record with their custom Exynos SOCs, and OneUI/bloatware for that long. (If you know, you know - and it seems like you know.)
Regarding specific models in question, US Mobile kinda complicates that... not because they of who they are, or the fact that they're offering SIM cards and plans on all three major networks now, but because of the underlying networks involved. If you're on a Verizon SIM, you'll need LTE Band 13, not a huge ask with high-end flagship smartphones, but still be aware. If you need a T-Mobile SIM, understand that you'll need their full 4G/5G band support on their network to ensure you have nationwide voice coverage, and fortunately OnePlus is a T-Mobile partner in this country. I won't bother with the AT&T headaches of their approved IMEI whitelisting for service and devices since AT&T access on US Mobile is past couple months recent.
But yeah, I think what you're looking for is a OnePlus 12. It's imperfect as you lose two of your key hardware features, because Apple design trends, but pretty much everything else is there and you can at least add back in a headphone jack through the USB-C port for $10. Otherwise, maybe the Nokia/HMD XR21 would be exactly what you want, though the security update lifespan on the Nokia at this point is significantly shorter, but it's also nearly half the price new.