If this is your experience, you've got other problems somewhere.
My wife and I live in an RV park and use the park's WiFi. Depending on the time of day, Speedtest.net shows we have between 10 and 20 Mbps, with around 6 - 10 Mbps up, using Xfinity fiber.
We use YouTubeTV for our TV, and I can't remember the last time we saw any buffering. Though we normally just do HD, when I've checked 4K, it doesn't buffer either.
In addition to using YTV, we also have a desktop computer, two tablets, 4 Kindles, 3 Alexas, and about 15 items running through WiFi smartswitches.
No problems. It just works.
Pretty much so.
I forgot to mention that I am also using VPN.. slows it down a bit more.