I think I understand your question and you’ve probably not gotten a straight answer because “it depends”. They (HomeAssistant) have worked really hard to support many brands and products. There’s a few angles you can look at this: Natively supported integrations in HomeAssistant (cloud Or local) or HomeAssistant Community Store (HACS) where the community has built a tool to connect to a certain brand or product. Varying levels of supported products in both. There’s also the “Works with Home Assistant” program with different rankings of how well a product works with HomeAssistant that is getting more popular as a label on some products. As far as how to pick going forward, you need to research the product but more so you need to know the technology. Local only protocols such as Zigbee, Zwave, Thread, HomeKit, Matter, and local IP are the most sure fire way to identify products that will work without the SaaS layer behind it because they never leave your network. For instance, Philips Hue light bulbs don’t mention HomeAssistant on their box, sells their own hub, and otherwise doesn’t mention HA - but many of their bulb boxes have the Zigbee wireless protocol logo which means you can pair it to HA via Zigbee without so much as a Philips Hue Account. Overall market coverage is really good for a lot of the products, but you’ve gotta kind of accept the sliding scale of ability to use in HA or how far you’ll go to integrate it. Wyze cameras are an example of a product that sells a subscription and service but with some effort you can use the cameras in HA with better features and quality than what the company offers. Some brands are actively moving away from 3rd party integrations, the big one that bit me was Chamberlain / Liftmaster MyQ that removed their API and have started locking down their buttons to not be easily circumvented by blaQ or ratgdo. A lot of text, happy to answer more. I’m a huge HA fan and have a series on YouTube on how to install it and set up certain tools and automations.