https://www.reddit.com/r/AndroidTV/comments/nkboqd/list_of_alternative_launchers_for_android_tv/

There's a list here with some discussion. There are also multiple discussions on this subreddit and https://www.reddit.com/r/ShieldAndroidTV/

I personally have been using FLauncher

Wolf launcher

ATV/Wolf didnt work well with my Shield 2015. Constant freezing of the shield where I needed to pull the plug to restart it. Settled on Sideload Channel Launcher 3

I'm not very techie, but following the easy instructions, I tried Wolf Launcher, I liked it and put it on my second box.

Captain America
(sorry, couldn't resist)

Wolf Launcher or Leanback Launcher.

I'm using Sideload Channel launcher 3: https://play.google.com/store/apps/details?id=dxidev.sideloadchannel3&hl=en_US&gl=US

It's not free, but I think it's worth it

I use FLauncher on my Shield Pro (2019)

Wolf Launcher all day long! See Techdoctor UK you tube channel for guidance. 👍

Unless you're constantly adding new apps, just disable Google Play Services and you get the old launcher back.