Hydrogen has many downsides that are not often talked about. Filling up is not easy in fact when there are almost no hydrogen stations in the world, as each one costs about 2 million to build while an EV charger costs a few thousand. Yes, the only emission is water, but the only emission of EVs is nothing. The efficiency is also very different. FCEVs are around 50% efficient on paper, but 30% efficient in practice, whereas EVs have an efficiency in the high 90s.
You’re quite mistaken that FCEVs don’t require rare earth metals. An FCEV basically is an electric car, it even has a lithium battery to buffer the output of the fuel cell. Fuel cells themselves use expensive, rare metals, wear out faster than batteries do and cost more to replace.
As solar energy storage, hydrogen is incredibly inefficient. Hydrolysis is a very lossy process. You would need about 10 times as many solar panels to store energy at the same rate as if you simply charged batteries, and the hydrogen rapidly leaks out of the storage tank if not used right away. Not a big problem for houses, but a big problem for cars, which often sit for long periods not being used.
These are the reasons why you don’t see FCEVs taking over. EV charging is getting faster and faster, soon FCEV won’t have this advantage over EVs anymore. Top of the line EVs already have range equivalent or superior to the only FCEVs currently available. The 2021 Toyota Mirai for example gets 400 miles to a tank. The highest spec 2021 Model S gets over 500.