My trick has been a simpler/faster/dumber HDMI switch that isn't the TV so that you can leave the TV on a single HDMI input and delegate any input switching to the the switch rather than the slow TV UI.

That adds extra complexity in terms of an extra remote. In my case, the simpler/faster HDMI switch is also the surround sound receiver so that moves volume as well to the simpler, dumber remote.

It's not ideal either, but reducing use of the TV's terrible UI is reducing temptation to just go back to the TV's terrible apps. (Also as the sibling option points out, the other trick is isolating the TV out of the network entirely. Sometimes the UI gets even slower to "punish" you for not allowing its smart features and ads to work, or the UI is just badly written and relies on a lot of synchronous waits for network calls for things like telemetry [six of one, half dozen of the other], which gets back to reasons to use a dumb input switch and get away from the TV's own UI.)