It is futile to expect the TV to be smart and support all sorts of apps and hardware only to be abandoned by the manufacturer years down the line. The only correct way to buy a TV imho is to hunt for a dumb but excellent display properties and get a streaming device such as Google TV Streamer, Apple TV or DIY x86 HTPC.
You can try Googling around for bespoke products but they will almost exclusively come from China and they will be very overpriced due to the soldered RAM.
TVs are made with BOM of like 10$ for the SoC, so it's the cheapest crap available.
Then again - none of the streaming services are streaming at anything remotely close to 100Mbps so I doubt they consider it necessary to upgrade to GbE.
I connected my Samsung TV to the WiFi for the first time two weeks ago because I wanted to play with the multi-screen-view thing, and it didn't appear to work with two HDMI cables.
It has not shut up asking me to update the fucking thing. Every time I turn the TV on, about twenty seconds later an update prompt will pop up, and it will not go away until I actively dismiss it. This happened even after disconnecting and forgetting the wifi. Never again.
What >100mbps content is there? 4K bluray just needs a bigger buffer to handle >100mbps spikes (Kodi for example offers this) and Moonlight/Apollo/etc is well into diminishing returns
4k blu-ray remuxes break 100mbps for long enough to cause problems on my TV, unless I use either wifi or the USB adapter. Others have done investigations showing in some movies the bitrate will exceed 100mbps for minutes at a time.