This is somewhat of a PSA because I see a lot of misinformation out there in Amazon reviews, Reddit posts, and elsewhere where folks are confused.

(Moderator note -- there are no Tapo smart switches in the model dropdown menu for this forum! Doh.)

Matter-support does NOT imply that a device uses Thread for transport. For example, all the current Tapo Matter switches work only over Wi-Fi. The Wemo and Eve switches support Thread but not Matter (yet, Wemo has put the indefinite brakes on Matter support, and Eve is planning it later this year with firmware upgrades). Unfortunately, both the Wemo and Eve switches fail miserably in 3-way circuits; they have really bad firmware bugs that keep the switches from being in sync with HomeKit state (perhaps other platforms too, not sure). Wemo at least acknowledges the bugs, but Eve refuses to do even that.

My current assessment of the state of the market:

Tapo provides the cheapest Matter single-pole switches and dimmers. They don't have 3-way Matter switches and dimmers yet. No Thread support. Tapo switches can't calibrate dimmers or set the LED mode if they're not connected to the Internet through their app -- and if they are connected that way, they'll blink orange at you if they can't reach the Tapo mothership. I consider this a terrible glitch that I hope they wil fix quickly in coming firmware. If they fixed that, added 3-way support and offered Thread as a transport, they'd have a killer product, rather than a pretty good one. Tapo csutomer support is reasonably responsive and good.

Eve provides 3-way Thread-based switches with Matter support coming later, but the current firmware is so buggy as to make 3-way flat out false advertising. It works in a 3-way with another Eve (although Eve support claims it doesn't, they're wrong). It works great as 2-way switch and doesn't have the phone home issues Tapo does. It doesn't support WiFi -- and Eve seems to be philosophically opposed to dimmers. Eve support is initially responsive but refuses to acknowledge problems -- for that reason alone, I won't use them.

Wemo provides 3-way Thread-based switches with Matter support possibly never coming, but the current firmware is so buggy as to make 3-way flat out false advertising. Wemo support is absolutely hideous. They take days or weeks to respond and are utterly incompetent at actually resolving any issues -- the only upside is that they at least acknowledged that their 3-way Thread models are buggy. Their older WiFi based models work much better but have a tendency to fall off the netwoork every month or so sometimes requiring a complete reset and reconfiguration to get them working again. Flaky, buggy, and terrible support, yuck stay wway

Leviton provides Matter 3-way switches which work well but require an companion switch from them; it will not work with a "dumb" 3-way switch in the circuit. They do not support Thread -- I haven't seen any mention of their intention to do so in the future. Their support is good. They are expensive.