What’s your recommended alternative?
The answer to the question I suspect that you're asking is that I've been enjoying my ChromeCast dongle.
Just don't. Roku is not exactly solving world hunger, it is not essential.
Or to rephrase my question - what should I use for streaming, for example, Netflix to my nice big tv?
It doesn’t. You need a set-top box. Those can run Roku, fire tv, chrome cast, Apple TV or something else. So for the third time - which of those does the OP which is so vehemently opposed ro Roku, recommend?
It’s not a hard question if you stop being snarky about it.
Google ChromeCast dongles cost a third or half as much a equivalent Roku gadgets. More importantly, Google doesn't make any attempt to prevent you from running vlc or mpv apps that you download.
Roku explicitly blocks 3rd-party media playing apps. The Roku media player has a terrible UI/UX and can't play many file codecs.
Also, Roku has nothing resembling a web browser app, whereas there are a few crappy web browsers available for Google devices. This isn't my use case, but it could be important for some.
Having spent time with both Roku and ChromeCast, I am hard pressed to present a single compelling reason to stay on Roku, much less choose it over Google.