A lot of times, the TV manufacturer is the one setting the standards for the streaming hardware. When they’re trying to keep costs as low as possible, they’ll skimp on the chip performance and memory. Those problems you’re seeing are likely due to underpowered hardware rather than issues in the OS. It can happen with any streaming OS. It you’re streaming on the TV and you have these problems, get an external streaming stick. Those are built for the streaming platform and will have better performance.
I tried that with my Toshiba Fire TV before I replaced it. It was… better. Not great. Still kind of sluggish. And the experience was worsened by the fact that I could find no way to make the TV default to the Fire Stick at start up. So I had to navigate through one Fire interface to select the input for the other. Lots of confusion as it could be difficult to tell which environment I was in, and of course, which remote I needed to use.
The best solution for me has been to bypass the TV OS and use a streaming device via my AVR (audio/visual receiver). After using Rokus, Fire Sticks and Google streaming devices I’ve settled on the Apple TV 4K for home viewing. It delivers excellent image and sound quality and has all the apps I need (except for a web browser which is no big deal).
For traveling I have a Fire Stick that works well with most hotel TVs if I can access the HDMI port. Some hotel TVs have a casting or streaming service option available now but I’ve found them to be kind of buggy and I’m disinclined to use my login on a public device.
I posted this about a month ago elsewhere: On my LG WebOS all of a sudden a video will stop playing; it just goes to the spinning circle and waits. In my case, it’s not just the Hulu app (which we use more than anything else because of its DVR), because when it hangs, it affects every other streaming app as well.
Everything is up to date, reboot doesn’t do anything, etc. I found the solution on a deep Google search that led me to a reddit forum, which had a fix that actually works. The fix: go to settings/general/location (or similar), change the country location from US to Canada, which restarts the tv. Then switch it back to US, and it works again (for a week or so). I suspect it has something to do with clearing a cache. Frustrating, but I haven’t gone to using a Roku stick yet.
Since it hasn’t happened lately, maybe the latest updates fixed it.
I can’t speak to that Toshiba TV with Fire, but on Roku TVs, there is typically a setting under “Settings->Power->Power on” which allows you to set the initial input when the TV powers up. I had to look that up on my Roku TV since I didn’t think to look there. There may be something similar on your Toshiba.
Another way to have the TV automatically switch to a port is to use the buttons on the external device’s remote and the TV will switch to that device. If your TV supports HDMI-CEC, which most do, then the external device can tell the TV to switch to the HDMI port of that device. Sometimes you need to go through your TVs settings to enable external control. It may be listed as HDMI-CEC or something like “Control external devices”.
As to the OP, I can’t say that I really have a preference of TV operating systems since I use them as little as possible. I got tired of dealing with the problems of the cheapo streaming hardware in the TVs and the resulting hangs, sluggishness, and crashes that I have an external streamers on all my TVs. For the streaming platforms themselves, I like Roku best best because I generally just want something to launch my apps without a lot of extra fluff and bloat. Chrome is good for people who want something that has a lot of integration with the apps. It can be nice to see the shows you’re watching on the home screen so you can easily jump back in. Fire also does that, but I don’t like how Fire seems to be an ad platform for Amazon products and services.