Android

I understand your bad experience with GSIs, but I think it's a step in the right direction. The way custom roms have been made through the years isn't sustainable for the long run. It's too much work for the few people involved, that goes obsolete so fast. But with GSis, the projects will one day be able to maintain just a few images, and the porting community will just have to focus on unlocking the devices.

GSIs aren't working 100% today, but it's something still new in the perspective of manufacturers, and the tendency is to have better support with time.

Just to put things into perspective, my experience, as someone poor from a third word country, is just the opposite. In the past, only the more expensive phones had custom rom support, and the cheaper ones I got access to, wouldn't even get results if I searched for the model on xda. Nowadays, even cheap chinese phones or the ones locally manufactured in here allow me to put a GSI and have a customized experience, up to date with security patches.

I have an android that has Mediatek Dimensity and I have found 0 custom roms that are good. I wonder why.

I think you meant it the other way around - "why custom ROMs have little device support" - right?

because for me it's clear that companies just want to ship their own spyware and bloatware.

Most manufacturers have made it more difficult to both make and install custom ROMs for their devices.

Pixel is the one big exception so far.

There are still plenty of custom ROM communities out there, but mostly for those cheap Chinese brands, especially those with snapdragon SoC. Enthusiasts using those devices usually aren't too afraid of breaking their cheap phones, so the communities are still thriving. On the other hands, people with $1000+ flagship phones are usually less likely to do this and void their warranty, unless their phone manufacturers aren't voiding warranty when you unlock the bootloader such as on pixel devices.

It just feels like I don't need custom ROMs anymore. Nowadays, most phones already do what I want them to do. I used to be pretty deep in the custom ROM community, but nowadays I don't even think about rooting my phone.

I guess the only use case for custom ROMs is the privacy aspect. But most people don't care about it, so the support is abysmal.

I am presently using a super niche device. SUPER niche. So niche that I have been dealing really closely with the manufacturer, who worked with Qualcomm and made a specific firmware just to get wifi calling working for me in Australia.

I have quizzed them so many times on why they won't support rom development. You can unlock the bootloader, but the rom files are heavily encrypted. There's no way to extract the boot IMG so we're dead in our tracks.

The manufacturer basically say that they have to fight so hard to gain google certification that they won't do a single thing to risk losing it.

They've been pretty generous with their warranty policies so probably another reason is they don't want to risk anyone doing overclocking etc and then having to cover device repairs or replacement.