This is absolute golden advice...you will find a bunch of "Tuya" devices on Ali that are supported on HE (via built-in or community drivers), but there are also a bunch that are not supported, and just as importantly, some that are supported but not recommended due to "spammy" behavior - they bombard the hub w/tons of needless status updates that can't be turned off and can eventually mess w/your hub's performance.
Less expensive sensors that are supported and liked by the community include Third Reality, Ikea, SonOff, etc.
Check these "Year In Review" topics for lots of favorite device recommendations from members of this forum:
And of course HE has their compatibility list (which will not included all the devices supported by community-developed drivers):
Correct. Though there is some support for bringing devices from Tuya and other hubs that support Matter into HE.
One community example:
And in a recent release HE now directly supports integrating Matter bridges & their devices:
