If only we had invented and built some sort of alternative mode of collective transportation. Maybe it could be in tunnels and ride on metallic rails. It would serve many people and make periodic stops to the same locations instead of the highway clusterf- we have today. Sad that we don’t, but a man can dream though. A man can dream.
Ohhh there are so many options here!
The app is often more important than the adapter at this point. Some marques have bad 3rd party app support unfortunately (looking at you, Subaru). Others have pretty great support (BimmerLink is adapter-agnostic, though they recommend using a high quality one and they have an affiliate deal of some kind with one manufacturer they recommend)
Personally I own a Chinese fake VCDS cable for <20 euros that allows me to do literal magic on anything VW, Audi, SEAT, Škoda… and could probably do a few things on modern Lamborghini and Bentley as well. Mysteriously, Porsche is the least supported out of all the VAG marques - they insist on having their own electronics. If I ever buy another VAG car, I’ll probably buy a genuine adapter to support the company behind it. I also own a Chinese fake Delphi DS150E clone, but at this point I don’t think it’s as great as it was 5-6 years ago. It doesn’t get cars newer than 2013. Plus it’s still missing some crucial things on some cars between 2000 and 2013. And outright missing some models.
Then there’s options like iCarsoft. More expensive than just an adapter and an app, but you get pretty great support for a lot of different marques. A lot more than some cheaper generic options.
And finally, marque-specific solutions. BimmerLink and VCDS I already mentioned, then there’s GAP for Land Rover, etc. Worth investing in if you’ve got a car you’re going to keep for a long time and want to be sure you can do stuff like air suspension ride height sensor calibration and all kinds of other procedures that generic tools might not have for your vehicle.