You can still hook it up using the composite or component cables, most UHD TVs still have component inputs on them. (Green, Blue Red for video, red and white for audio)
I'm curious, which models are you referring to? From what I've seen most modern TVs have a couple of HDMI ports at best and only those cheap Chinese TVs had composite/component and SCART connectors as well. Few months ago, I found a decent Panasonic 39" 3D TV with 3 HDMI ports and component and SCART connectors as well, but that was pretty much the best thing I could find for a decent price.
In addition, in case you're seeing distorted black and white image, make sure to switch from component to composite video output on your TV.
I do have several hdmi ports, however when I fire up the wii, I get a msg from the TV which says mode not supported. It's been tested with several wii models and two different cheap Wii2HDMI which can be found on ebay for about 3-5$
I I'm not sure I have composite connection in my TV but will check
I have never seen a SCART connector on any TV in-person, in my entire 41 years of being alive.
I got my 4K TV in early 2020, and it still has them. I think it's just the cheaper low-end models that are cutting them.
