I just recently got the Samsung S10+, and have rooted it. It was much harder to root than my old Samsung J5 2017, which Samsung did on purpose. When I rooted I relized I couldn't use apps such as Secure Folder, Samsung Health, and Samsung Pay. I tried unrooting, but I Samsung wouldn't let me relock the bootloader. And even if I somehow relocked the bootloader, it still couldn't use the apps, because there is an E-fuse inside the CPU which I can't fix.
So my question is, Why does Samsung and other manufacturers go out of their way to stop rooting?
Any company will care if you alter their device. If I buy a car, then make alterations, while they can't stop me from doing so, they can then not cover anything I altered or anything that it effects. Which can lead to a lot not being covered.
It is the same with computers, phones, tablets, and a lot of other things. If you want them to cover the device, then you can't make any significant changes to it that are damaging or permanent.
On top of this, it is really easy to brick a device by rooting it, or to add things to it that will happily steal your info, etc.
If you want a device that can do things you want it to do, then you either need to find one with the options you want, or create your own device.
You can't even do significant modifications to a home you own in most places without paying for permits, etc.
But then you are at your own risk of things not working in your car once you modify it. There are really only two reasons computer vendors block security and program access, for reliability and security and for keeping you locked to services and products. First is pretty clear as to why, second is due to your licensing agreements (say if you want to bypass a tethering option not available for your service).
There have been many lawsuits filed to keep car repair available outside of official car dealerships. Try putting in your own shocks then trying to get them fixed under your car warranty.